Brakes ...... Overdue write-up. (2 Viewers)

[ShenValley100LC]

If flare nut threads of pipe actually damaged. You can also replace the hard line, save brain damage.

I "may" have listed, flare nut size here: If not, measure diameter and count threads. Any flares nuts you may end up getting, test fit first. Most you find at parts store that are metric, are the correct size and count.

Installing SS Braided Brake lines, Flare nut stuck in pipe!

Ok this I've not seen this before. What appears to be a factory installed, brake hose from main pipe to differential pipe flare nut is stuck on female end. While removing the two upper rear brake hoses, the flare nut of one hose was hard to turn, as if cross thread. But now that threads are...

forum.ih8mud.com

Also get the metric flaring maker kit, not SAE. If you go that route!

It's the masters soft threads, that tend to get damage. Get picture of threads, zoom in. See which and if damaged.

Some thread flare nut damages, is form hit on threads of flare nut. While muscling out & in master. To this end I rubber cap flares as I pull from master. I also use the carboard, that comes in top of OEM brake masters box. As a shield, between master & all hard lines as I install master in engine bay.

If flare nut threads or female threads of master, not to badly damaged. A thread chase may fix them.

But, check a few things first:

Often times, it's a matter of getting flare nut line-up with female threads of master.
Also make sure flare nut, spins easily on pipe. A drop of oil on pipe, helps.
Always thread flare nut, all the way on be hand. Pulling outward on pipe, as nearing bottoming. Helps center pipes female flare to male in master.

Good luck.

My flare nut turned out to be completely fine, I got a new flare nut and just to make it was the right size attempted to put in the master cylinder (drivers side port), it would not go in. I got a M10x1.00" tap and die set. Put the thread chaser on my flare nut, spun on just fine, nothing wrong with it. I put the thread tap in the master cylinder and reworked the female threads, cleaned out some steel shards, and it went on. Not sure what happened on that port but I saw several others at issue on that same one.

Anyways, I got everything buttoned up and bled the breaks using 5 12oz bottles of Toyota Dot III, but I just am now seeing that you are apparently supposed to use techstream to bleed the abs, do I have to get tech stream? or is this not actually necessary.

 

[2001LC]

My flare nut turned out to be completely fine, I got a new flare nut and just to make it was the right size attempted to put in the master cylinder (drivers side port), it would not go in. I got a M10x1.00" tap and die set. Put the thread chaser on my flare nut, spun on just fine, nothing wrong with it. I put the thread tap in the master cylinder and reworked the female threads, cleaned out some steel shards, and it went on. Not sure what happened on that port but I saw several others at issue on that same one.

Anyways, I got everything buttoned up and bled the breaks using 5 12oz bottles of Toyota Dot III, but I just am now seeing that you are apparently supposed to use techstream to bleed the abs, do I have to get tech stream? or is this not actually necessary.

It can be done without tech stream. Although I do like using tech stream air bleed, on new masters.

You can just bleed all 4 corners. Once all air, bleed out of system, pedal should feel normal (firm) with IG key ON. Test booster motor run time. By pumping pedal 40 times, with IG key OFF. Then, with at least 12.4volts showing on battery. Turn IG key ON, and time, how long booster motor runs. I see about ~28 seconds with new master assembly. If over 40 seconds, book (FSM) states; re-bleed (either air in system or a leak).

Then (once you air out, and have good brakes) go for drive on dirt road. Get up to ~35 MPH, and stomp on brakes, activating ABS. Do this 3 or 4 times.

Tips:

• Keep reservoir level above low line, at all times while bleeding.
• I use a can of brake cleaner and HP air. To dry flare nut threads & pipe of all brake fluid & oil.
• After active using brakes with IG key ON, to build pressure at flare nuts/pipe. After which, I use my finger, and wipe threads & pipe. Any wetness on my finger at this point, indicates a weep/leak. We can not have any weeps/leak, not any!
• Don't spill any, while pouring bake fluid in reservoir. We don't want any, running down onto brake control wire.
• Clean spills with water ASAP. Any on body, frame, etc. Brake fluid will remove paint, if not washed away fast.

Tips: For next person attaching a flare nut:

1. Clean threads of flare nut and pipe that passes through it. Female threads on master should be clean, and their temp threaded plastic plugs, be keeps in, until attaching hard line/flare nut.
2. Put a drop of oil on pipe, where it passes through flare nut. Make sure flare nut spins easily on pipe. Do not get oil on outer funnel tip of flared pipe. We do not want any oil, getting into master.
3. Expert trick, if having trouble threading on flare nut in by hand. Use a very tiny drop of oil on threads of flare nut. Be careful to only use a tiny amount of oil. We do not want any oil getting into master.
4. Most important. Thread flare nut on, BY HAND! This way, it is not possible for the average person to cross-thread, at least not without feeling it bind.
5. As flare nut starts to bottom. Pull lightly, squarely and evenly out on pipe. So that flare nut pulls, flare of pipe into masters cone/tit squarely. This helps seat flare of pipe squarely into cone/tit in master.
6. Torque flare nut to maximum of 108 INCH-lbf. (9ft-lbf) If threads oiled, reduce torque to maximum of 84INCH-lbf (7ft-lbf). Do not over torque, or the flare nut may get mushroomed.

 

[ShenValley100LC]

It can be done without tech stream. Although I do like using tech stream air bleed, on new masters.

You can just bleed all 4 corners. Once all air, bleed out of system, pedal should feel normal (firm) with IG key ON. Test booster motor run time. By pumping pedal 40 times, with IG key OFF. Then, with at least 12.4volts showing on battery. Turn IG key ON, and time, how long booster motor runs. I see about ~28 seconds with new master assembly. If over 40 seconds, book (FSM) states; re-bleed (either air in system or a leak).

Then (once you air out, and have good brakes) go for drive on dirt road. Get up to ~35 MPH, and stomp on brakes, activating ABS. Do this 3 or 4 times.

Tips:

• Keep reservoir level above low line, at all times while bleeding.
• I use a can of brake cleaner and HP air. To dry flare nut threads & pipe of all brake fluid & oil.
• After active using brakes with IG key ON, to build pressure at flare nuts/pipe. After which, I use my finger, and wipe threads & pipe. Any wetness on my finger at this point, indicates a weep/leak. We can not have any weeps/leak, not any!
• Don't spill any, while pouring bake fluid in reservoir. We don't want any, running down onto brake control wire.
• Clean spills with water ASAP. Any on body, frame, etc. Brake fluid will remove paint, if not washed away fast.

Tips: For next person attaching a flare nut:

1. Clean threads of flare nut and pipe that passes through it. Female threads on master should be clean, and their temp threaded plastic plugs, be keeps in, until attaching hard line/flare nut.
2. Put a drop of oil on pipe, where it passes through flare nut. Make sure flare nut spins easily on pipe. Do not get oil on outer funnel tip of flared pipe. We do not want any oil, getting into master.
3. Expert trick, if having trouble threading on flare nut in by hand. Use a very tiny drop of oil on threads of flare nut. Be careful to only use a tiny amount of oil. We do not want any oil getting into master.
4. Most important. Thread flare nut on, BY HAND! This way, it is not possible for the average person to cross-thread, at least not without feeling it bind.
5. As flare nut starts to bottom. Pull lightly, squarely and evenly out on pipe. So that flare nut pulls, flare of pipe into masters cone/tit squarely. This helps seat flare of pipe squarely into cone/tit in master.
6. Torque flare nut to maximum of 108 INCH-lbf. (9ft-lbf) If threads oiled, reduce torque to maximum of 84INCH-lbf (7ft-lbf). Do not over torque, or the flare nut may get mushroomed.

Perfect, got it all buttoned up bled, and did the hard stops on some wet and gravel roads. After 40 brake pump and the key on motor stopped at 30 seconds. Do I need to bleed again after the hard stops activating the ABS?

 

[2001LC]

Perfect, got it all buttoned up bled, and did the hard stops on some wet and gravel roads. After 40 brake pump and the key on motor stopped at 30 seconds. Do I need to bleed again after the hard stops activating the ABS?

I don't know if, any of the factory storage/shipping fluid was in ABS valves. If so activating ABS, should have moved fluid. If you want to bleed again, it can't hurt. As it will move more fresh fluid through.

I've tried TS air bleed and manual bleed, after driving activation of ABS. I've never seen more air bubbles, after drive BS activation.

30 seconds bit long, which likely due to battery voltage a bit low (11.9 to 12.2volts). But 30 seconds, indicates no air or leaks in system. So you're good!

Just make sure "that" a bleeder not weeping.

You're good to drive next "25" years. Just flush every 2 to 3 years, and never overfill or spill brake fluid.

 

[ShenValley100LC]

Much thanks to this Forum and @2001LC with the answer to many questions. My advice that might help someone is if your car has sitting in your driveway for extended time while you are diagnosing, waiting for parts, and installing, etc. and upon install the new unit you may want to make sure that your battery isnt drained or the terminals loose. Upon install my master cylinder didnt fire up and then I check the battery and it was low and my terminal was loose from when I took it off during install. I put a trickle charger on it and tightened and everything worked great.

And double emphasis on @2001LC advice to use Toyota DOT III and dont overfill, I saw several videos where after the master cylinder cycled pumping fluid into the lines it brings the reservoir closer the min line and they refilled the reservoir again to the max line, this may cause the reservoir to overflow when you do the 40 brake pumps since it send fluid back into the reservoir. Yes, you dont want it to go below the min line but if its still above the min and the M/C has just cycled you dont really want to fill it to the max line because the fluid will go back to the max line when you pump the brakes.

also if you know this job is coming up the "10mm" flare nuts and bleeders on these land cruiser are slightly undersized, standard 10mm flare nut wrenches are a bit loose on them and mash the edges, you can still do it (and I did) but I wish I had grabbed an undersized one beforehand.

 

[Rpreme]

Hey guys I got a quick question….

I ordered my OEM brake pads and shim kits last week and decided to get them installed this week. The rear pads and shim kits fit perfect, but the fronts looked kinda weird and don’t fit the shim kits fully. Need some assistance on if I have the right front pads or not. Had the dealership verify my VIN and all. I have a 1998 and I don’t know if parts have been superseded.

Front Pads - 04465-60020 (Different from what I had on the truck)
Front Shim Kit - 04945-60020 (Doesn’t fully fit the above pads)
Rear Pads - 04466-60070 (Installed no problems)
Rear Shim Kit - 04946-60031 (Installed no problems)

Any help would be appreciated.

 

[2001LC]

Frt pad 04465-60220. 1998 LC/LX. Replaces: 04465-60120, 04465-60150, 04465-60151

 

[Rpreme]

Frt pad 04465-60220. 1998 LC/LX. Replaces: 04465-60120, 04465-60150, 04465-60151

Thanks for verifying this.

It seems Toyota sent me the wrong front pads. Getting this corrected now.

 

[Felix Spain]

Master replacement only current cure, If screeching sound with bubbles!

The screeching sound with bubbles (wake seen in reservoir fluid) coming up front of reservoir. IMHO a sign, a seal in forward point of master cylinder, is damaged. The seal can no longer handle the higher pressure developed by booster system, coming up to near factory peak pressure. So brake fluid under pressure passes it. This produces the screeching sound. Wake in reservoir is the fluid escaping (passing seal) into reservoir from back (forward of vehicle) master cylinder. This seal (currently) we've no way to replace, except by replacing Master.

At first sound (screech) for short burst and mostly when cold. As day warms or brakes used, heat expansion takes place. Then sound stops. Same happens with caliper seals, when brake applied. But without the screech sound. With these caliper piston seal damage, we do we get brake alarms, that go away when seals warmed up. Brake fluid itself, gets very hot with use. So either use or hot days will increase size of seal (heat expansion). Then when cold (cold shrinkage). So issues come and goes with cold and heat.

Over time these seals with fail. They not hold pressure any longer, even hot.

Why some 100 series seals fail, yet others do not. It has to do with brake fluid condition. Proper flushing is so important a PM.
Seal failure: "May" also have to do with brake fluid brand and type.

Note:
Bubbles are not accurate or great word to use. "Wake" in reservoir fluid is probably better. IMHO this is a rapid release of fluid under very high pressure, into reservoir.

Most will not even hear the early shot burst screeching. Why, ambient sounds. Like chimes, Radio, Cabin fans. I make sure all electricals, shut down before I turn key off when parking, OM suggest this. I turn on IG key and wait for all sound (chimes & pump) to stop, then I start.

Here are the seals that IMHO are failing. Toyota does not sell, nor are they designed to be R&R.

View attachment 3348995View attachment 3348996


View attachment 3348998

View attachment 3349000

It is mentione that the seals are not servicable and not provided by Toyota. However, I believe I have seen them, here is an example:

Genuine Brake Master Cylinder Seal Repair Kit with ABS

Fits models with ABS and with a 4 bolt hole mounting to the servo

www.roughtrax4x4.com

or are they diffferent?

 

[2001LC]

It is mentione that the seals are not servicable and not provided by Toyota. However, I believe I have seen them, here is an example:

Genuine Brake Master Cylinder Seal Repair Kit with ABS

Fits models with ABS and with a 4 bolt hole mounting to the servo

www.roughtrax4x4.com

or are they diffferent?

The P/N 04493-28090 does not state for USA 100 series, nor does pic look like seals which you can see here on page #2:

Brakes ...... Overdue write-up.

How long have you owned the truck? Before you spend money on parts & labor; have the booster pressure tested ( by someone capable and honest) In the FSM (service manual) in the Brake section (BR) (BR-40 in the 04 manual) Is the beginning page of testing procedure. Roger that - great...

forum.ih8mud.com

P/N 04493-28090 you link:

Vehicle Compatibility​

Below are a list of compatible vehicle for this product.

---

• TOYOTA LAND CRUISER HDJ80R 4.2CC (1HDT) DIESEL (12 VALVE) RHD (G - L REG, 1/1990-7/1994) UK
• TOYOTA LAND CRUISER HDJ81 4.2CC (1HDT) DIESEL (12 VALVE) RHD (G - M REG, 1/1990-1/1995) IMPORT
• TOYOTA LAND CRUISER FZJ80 4.5CC (1FZFE) STRAIGHT-6 PETROL (EFI) RHD (K - S REG, 1/1990-1/1998)

 

[MissouriLC]

Paul (@2001LC): great master thread on this issue. I am interested to see that you are now personally replacing the entire MC assembly on the vehicles on which you're working.

Just this past Monday (eclipse day!), as we were preparing to head down to southern Missouri to watch the eclipse, I got the alarm/warning lights and no brakes again. Remember, I had my accumulator pump motor rebuilt not quite 5 years ago. I was able to do some electrical diagnostics, and everything points to an intermittent failure of the pump to run. Likely a worn commutator again. Also, it seems as though the pump has been running more frequently and longer lately, and the system seems to completely bleed down pressure overnight (it used to not COMPLETELY bleed down in 12 hours). I suspect that a combination of weak seals and a weakened accumulator is at play.

After some thoughtful consideration, I decided to buy to the full MC assembly. Hopefully it should be arriving tomorrow. I look forward to inspecting my current unit for evidence of leaks, etc. and also checking the condition of the motor. I will post my findings for the benefit of this catalogue of empirical evidence.

While I think my past diagnosis and "rebuild" of my system was worthwhile, I agree with your current assessment of replacing these units. With most of these cars now approaching--and many exceeding--25 years old, I concur that rebuilding these assemblies is no longer worthwhile. IIRC, the cost of the whole unit replacement was also higher back then than it is today.

I still maintain my position on treating these systems as baselining/preventative maintenance. If you are buying a new-to-you Hundy, just plan on replacing the MC assembly as you would plan on replacing the timing belt. Thankfully, the MC replacement is a lot easier to DIY than the timing belt!

Best,
Tim

 

[2001LC]

Paul (@2001LC): great master thread on this issue. I am interested to see that you are now personally replacing the entire MC assembly on the vehicles on which you're working.

Just this past Monday (eclipse day!), as we were preparing to head down to southern Missouri to watch the eclipse, I got the alarm/warning lights and no brakes again. Remember, I had my accumulator pump motor rebuilt not quite 5 years ago. I was able to do some electrical diagnostics, and everything points to an intermittent failure of the pump to run. Likely a worn commutator again. Also, it seems as though the pump has been running more frequently and longer lately, and the system seems to completely bleed down pressure overnight (it used to not COMPLETELY bleed down in 12 hours). I suspect that a combination of weak seals and a weakened accumulator is at play.

After some thoughtful consideration, I decided to buy to the full MC assembly. Hopefully it should be arriving tomorrow. I look forward to inspecting my current unit for evidence of leaks, etc. and also checking the condition of the motor. I will post my findings for the benefit of this catalogue of empirical evidence.

While I think my past diagnosis and "rebuild" of my system was worthwhile, I agree with your current assessment of replacing these units. With most of these cars now approaching--and many exceeding--25 years old, I concur that rebuilding these assemblies is no longer worthwhile. IIRC, the cost of the whole unit replacement was also higher back then than it is today.

I still maintain my position on treating these systems as baselining/preventative maintenance. If you are buying a new-to-you Hundy, just plan on replacing the MC assembly as you would plan on replacing the timing belt. Thankfully, the MC replacement is a lot easier to DIY than the timing belt!

Best,
Tim

You've a good handle on the issue.

You are correct. Toyota drop prices of brake master w/booster (the whole deal) in 2021 IIRC, by about $1k. Even Dealership, which were changing ~$5K installed, have drop to under $3K.

Where one, can rebuild the booster motor, replace the accumulator or just replace the whole booster assembly (motor, pump, accumulator) with new OEM. In most, it's not long-term cost effective. It's also, less time consuming to replace the whole master w/booster in one shot.

On some of my own 100 series. I have rebuild components of the master ( master, ABS, boosters motor, etc.). Some stuff I've not written about. I do these as research, to get better understanding of master.

Bottom line. We can get 25yrs even more use from a brake master, that is well cared for. How long we don't know. But once we negative signs or a failure. Replace the whole master w/booster, is best course of action.

 

[rexington14]

I still maintain my position on treating these systems as baselining/preventative maintenance. If you are buying a new-to-you Hundy, just plan on replacing the MC assembly as you would plan on replacing the timing belt. Thankfully, the MC replacement is a lot easier to DIY than the timing belt!

Is the recommendation that the MC be replaced purely due to age, even though it may be functioning ok and within spec (no strange noises, no leaks, no reservoir staining, motor run time under 40 sec on startup)?

At around $1500 for a DIYer and $3k for a dealership to do it, that's a hefty price for something that may have more service life left in it.

Personally I've held off on the MC replacement, as mine appears to function within spec (mine's an 05). I actually just flushed 7 quarts of fresh Toyota DOT3 through it when I did a rear brake job in hopes I can hold off on this even longer.

 

[NE Snowman]

There is no feeling like hitting the brake pedal and it goes to the floor, those who had it happen can relate I’m sure(happened in a work van, rusted line). No brakes can cause serious problems, I was lucky. To me… that’s worth $$$$.

Mine gave me a warning, slow weeping from master into abs, left spots on my inner fender. My res was heavily stained as well.

It was on my 200k PM list, replaced @ 182k.

Things I tend to favor PMing are things that leave you stranded. Starter, brakes, alternator, cooling system. To me it’s convenience; really try to avoid ruining a long road trip with vehicle problems. My work van I let more go, a minor pull over or tow locally isn’t a big deal.

 

[MissouriLC]

Is the recommendation that the MC be replaced purely due to age, even though it may be functioning ok and within spec (no strange noises, no leaks, no reservoir staining, motor run time under 40 sec on startup)?

At around $1500 for a DIYer and $3k for a dealership to do it, that's a hefty price for something that may have more service life left in it.

Personally I've held off on the MC replacement, as mine appears to function within spec (mine's an 05). I actually just flushed 7 quarts of fresh Toyota DOT3 through it when I did a rear brake job in hopes I can hold off on this even longer.

Personally, if I was buying a new-to-me 100, or if I was due for a brake flush (or replacing a caliper or anything else that required bleeding the brakes), I would pull the MC, remove and open the motor, and inspect the commutator and brush wear (along with condition of the motor's power wire). In the event that any of that seemed excessively worn, I would opt to replace the entire MC assembly, as opposed to rebuilding/replacing one or more individual components.

Of course, if things didn't seem excessively worn and it was working in spec, no need to replace.

Fortunately, the first time mine crapped out I was 2 miles from home, and the second time the truck was in the garage. I shudder to think of a scenario where I was hundred or more miles from home and suddenly without brakes!

 

[rexington14]

Personally, if I was buying a new-to-me 100, or if I was due for a brake flush (or replacing a caliper or anything else that required bleeding the brakes), I would pull the MC, remove and open the motor, and inspect the commutator and brush wear (along with condition of the motor's power wire). In the event that any of that seemed excessively worn, I would opt to replace the entire MC assembly, as opposed to rebuilding/replacing one or more individual components.

Of course, if things didn't seem excessively worn and it was working in spec, no need to replace.

Fortunately, the first time mine crapped out I was 2 miles from home, and the second time the truck was in the garage. I shudder to think of a scenario where I was hundred or more miles from home and suddenly without brakes!

Knock on wood this hasn't happened to me... but don't you get the alarms and Xmas tree dash lights when a failure is imminent? And isn't the system designed from a safety perspective so that there is at least enough braking power to make a couple full stops to pull over? Now of course no one wants to be disabled on the side of the road, but hey, stuff happens. The scenario of doing 70+ on the highway and then without warning out of nowhere your brakes are completely gone and your bound to have a collision, isn't likely, unless you cant see or hear.

All that said, eventually I will DIY mine as a PM, (maybe at the next Toyota parts sale lol). But in the meantime, because I do routinely inspect / flush the unit, I'm not really driving around scared that my MC is going to die on me at any moment.

 

[MissouriLC]

Knock on wood this hasn't happened to me... but don't you get the alarms and Xmas tree dash lights when a failure is imminent? And isn't the system designed from a safety perspective so that there is at least enough braking power to make a couple full stops to pull over? Now of course no one wants to be disabled on the side of the road, but hey, stuff happens. The scenario of doing 70+ on the highway and then without warning out of nowhere your brakes are completely gone and your bound to have a collision, isn't likely, unless you cant see or hear.

All that said, eventually I will DIY mine as a PM, (maybe at the next Toyota parts sale lol). But in the meantime, because I do routinely inspect / flush the unit, I'm not really driving around scared that my MC is going to die on me at any moment.

It’s true… the warning beep and Christmas tree are unmistakable and should never be ignored. But, if the pump motor stops working—depending on how much pressure is left in the accumulator—you have one to four applications of the brakes before that accumulated pressure is exhausted. So, you’re unlikely to crash, but you will be stranded. The first time mine failed, I was able to drive it the two miles back home on surface streets. I live in the “inner city”, so I could select a route with minimal traffic. Stopping needed downshifts, standing on the brakes, and use of the parking break. It was a hair-raising experience!

In short, I think it all depends on your tolerance for being stranded! If you pull over immediately when you hear the alarm, you’ll have enough brakes left to do so safely. However, this failure does come on suddenly and typically without any other obvious advance symptoms. I wouldn’t want to be at a remote campsite or on the highway when it happens. For me, the peace of mind is worth the cost/labor.

 

[MissouriLC]

Pulled the MC last night and, since it was my second time doing this, it took me about 40 minutes from start to finish. I didn’t have time to fully disassemble the unit, but I did pull the motor off and open her up…

Brushes are fully worn down, with lots of carbon dust in the motor housing.

Bad pic, but the commutator actually shows very little wear.

Motor control wire and lugs are also in good shape.

In my limited experience with motors, this amount of brush wear in five years would suggest excessive runtimes, precipitating carbon contamination would further wears down the brushes. Again, likely because the pump was fighting against an MC assembly that wasn’t holding pressure to spec.

 

[2001LC]

I do not, advocate replacing Brake Master as a PM. I've seen many very old, with very high mileage, doing just fine.

I grade the brake Masters:

• A master that passes grading with flying colors. I've no concern with.
• If it gets a poor grade. I make aware, it will fail sooner rather than later. But even one with a bad grading scored, can last for many years!

But understand:
All brake booster motors, will, one day fail. Pedal goes to the floor. No brakes or very little stopping power at very bottom of pedal.
Nitrogen gas in accumulators, deplete with time. Results in weak brakes, taking extra foot pedal pressure to stop.
Flexible lines will burst, and must be inspecting for signs (bubble). Braking to it's wheel (caliper), is lost. Others wheel still have braking, until fluid get to low.

 

[2001LC]

Pulled the MC last night and, since it was my second time doing this, it took me about 40 minutes from start to finish. I didn’t have time to fully disassemble the unit, but I did pull the motor off and open her up…
View attachment 3605024
Brushes are fully worn down, with lots of carbon dust in the motor housing.
View attachment 3605026
Bad pic, but the commutator actually shows very little wear.
View attachment 3605027
Motor control wire and lugs are also in good shape.

In my limited experience with motors, this amount of brush wear in five years would suggest excessive runtimes, precipitating carbon contamination would further wears down the brushes. Again, likely because the pump was fighting against an MC assembly that wasn’t holding pressure to spec.

Hard to see, but look a little wet inside motor. If so, that also reduces life. There's a breather hole to motor and drain for pump. They must not be clogged. Or fluid is sucked into motor.