Known problem with original calipers for a 1983 FJ60 ? (1 Viewer)

[fjgdk]

Was there a known problem with the design or something of the FJ60 calipers from the factory ?

The reason I ask is that in my front axle work, initiated by a leaky and seized passenger side caliper, I am finding the driver's side caliper to have seized (but not leak) in the same piston as the passenger side caliper. It seems one of the smaller bore pistons View attachment 1436839 View attachment 1436840 on the half without the actual brake line connection seized in both. Is this just shear luck in dealing with a formerly 1-owner 1983 FJ60 with 283K miles or was there some known defect pattern?

I have the OEM seal rebuild kit, 8 new OEM pistons, the ever-elusive red "Toyota rubber grease" for lubricating all things in the pot all made affordable by ayamaya.com. I am also using a different grease than the red rubber grease for the pins etc. stuff not in the piston pots. I am weary of unknown rebuilds and have rebuilt calipers before, just not for an FJ60, so I actually prefer to go this more expensive seemingly illogical route haha.

Below I am showing the driver's side caliper, with the formerly seized piston evident in it's difference from the other used pistons. I am lazy and don't want to scrounge for the passenger side but the effect was the same. While ultimately the driver's side was in better shape than the passenger side, it still required me to use heat to try to remove the stuck piston, which didn't work so well, followed by letting it sit 3 days submerged in a bucket of evapo-rust. Evapo-rust was my hero.

 

[GeologistFelix]

No idea about how common that problem is, but regardless of that, it looks like the result of going too long without flushing the fluid, and that pitting is from water-related corrosion. Brake fluid soaks up water from the air almost like a sponge, and even with a 'perfectly fine' cap on the master cylinder, it will eventually get a fair amount in the system. Not only having water in solution with the fluid lower the boiling point of your brake fluid, but it also makes the fluid mildly corrosive to metal, including the stainless(?) steel they make those pistons out of. Lots of heat/cool cycles with 'wet' brake fluid will pit just about anything. I could see this happening with a well-cared-for rig that was 'lucky' enough to not have any other brake hydraulics fail until now, so it didn't get the brake fluid flushed more than once or twice in 30+ years.

All of that explanation goes right in out the window if you've been flushing the brake fluid with any regularity, of course. Plus, this is just me speculating wildly, having never rebuilt a caliper, so take it with a grain of salt, especially if someone else has some first-hand knowledge about this.

That definitely looks like 'hot metal repeatedly exposed to acidic/alkaline water' pitting, though. The fact that it's the same piston on both sides makes sense with how the water would separate from the brake fluid and sink to the bottom when it overheats, boils, and condenses (or are the smaller pistons on top? Maybe I have it backwards).

Anyway, good luck.

 

[Spike Strip]

Interesting that you'd consider a brake caliper with unknown brake fluid maintenance that lasted for 34 years as having a 'design flaw' ...

Just sayin' .

 

[hj 60]

Strange that only one is pitted so bad.
No idea what happened.
maybe from factory one rubber seal was damaged/missing.
Mine all had equal pitting:

 

[fjgdk]

Interesting that you'd consider a brake caliper with unknown brake fluid maintenance that lasted for 34 years as having a 'design flaw' ...

Just sayin' .

Yes that was not good logic or wording on my part.

No idea about how common that problem is, but regardless of that, it looks like the result of going too long without flushing the fluid, and that pitting is from water-related corrosion. Brake fluid soaks up water from the air almost like a sponge, and even with a 'perfectly fine' cap on the master cylinder, it will eventually get a fair amount in the system. Not only having water in solution with the fluid lower the boiling point of your brake fluid, but it also makes the fluid mildly corrosive to metal, including the stainless(?) steel they make those pistons out of. Lots of heat/cool cycles with 'wet' brake fluid will pit just about anything. I could see this happening with a well-cared-for rig that was 'lucky' enough to not have any other brake hydraulics fail until now, so it didn't get the brake fluid flushed more than once or twice in 30+ years.

All of that explanation goes right in out the window if you've been flushing the brake fluid with any regularity, of course. Plus, this is just me speculating wildly, having never rebuilt a caliper, so take it with a grain of salt, especially if someone else has some first-hand knowledge about this.

That definitely looks like 'hot metal repeatedly exposed to acidic/alkaline water' pitting, though. The fact that it's the same piston on both sides makes sense with how the water would separate from the brake fluid and sink to the bottom when it overheats, boils, and condenses (or are the smaller pistons on top? Maybe I have it backwards).

Anyway, good luck.

This sounds like a good explanation and makes alot of sense given that I know who owned it since purchase but don't know the total history of the brakes. Assuming that simple neglect of the brake fluid is the culprit, how screwed will I be if I finish this front axle job and don't replace ALL the lines in the whole brake system ? I am replacing the hard line to the caliper from the backing plate as well as the rubber hose part to the backing plate. I'd like to replace all the lines on the truck though, but I've had this front axle apart since the beginning of the winter in an covered carport and want to get it back together so I can get it to an enclosed garage and do alot more work on it. I don't notice leaks from the remaining hard lines. Should I be able to put it back together, including a new master cylinder, bleed everything and have enough safe braking power that I can get it into a garage I will be renting to do much more work on the thing ?

 

[Landpimp]

small one toward the bottom or top? (I forget) but my guess its that is where moisture gets trapped.

trying to think of which have seized/stuck most often on mine(not just 60) over the years......I seem to think it was almost always the lower of the pistons.

I don't know what the rebuild kit costs.....but for $50 you can get a OEM reman caliper from Toyota.....which is as high as quality reman you can get(that I know of)

are you the original owner of the 60? if not there is no way to know if those are the original calipers.

 

[fjgdk]

Strange that only one is pitted so bad.
No idea what happened.
maybe from factory one rubber seal was damaged/missing.
Mine all had equal pitting:

Yes it is strange that your's all had equal pitting.

Are you rebuilding with OEM pistons ? It seems that using the proper Toyota "rubber grease" (vs. caliper pin grease) is critical for the proper rebuilding of these calipers.


Also, the passenger side rotor was more of the "Original" style, with six holes for the wheel lugs and two holes for the smaller screws to fasten to the wheel hub. The driver side rotor, while the same diameter as the passenger side, did NOT have the holes for the two smaller screws. Seems like the rotors were not changed evenly.

The current OEM Toyota rotors that I purchased for this job are larger in diameter than the two old rotors and do not have the two smaller screws.

 

[fjgdk]

small one toward the bottom or top? (I forget) but my guess its that is where moisture gets trapped.

trying to think of which have seized/stuck most often on mine(not just 60) over the years......I seem to think it was almost always the lower of the pistons.

I don't know what the rebuild kit costs.....but for $50 you can get a OEM reman caliper from Toyota.....which is as high as quality reman you can get(that I know of)

are you the original owner of the 60? if not there is no way to know if those are the original calipers.

The small ones are towards the bottom.

No I am not the original owner, but I bought it from the original owner. That being said, you are 100% correct, buying from the original owner in no way means I have the original calipers.

 

[fjgdk]

Strange that only one is pitted so bad.
No idea what happened.
maybe from factory one rubber seal was damaged/missing.
Mine all had equal pitting:

Can you show a photo of the stamping/marks on the side of your calipers ?

 

[fjgdk]

Also, I dug out the passenger side caliper and the old pistons from it. I already painted and cured the passenger side with black and glossy caliper paint. Need access to the high cfm compressor again to soda blast the driver side caliper.

The overall condition of the passwnger side pistons is much worse than the driver side pistons. You can probably tell which was the frozen small one on the passenger side.

 

[Spike Strip]

I've seen those pistons available aftermarket, if you're interested in replacing. But the cost makes it silly not to just buy remfg'd calipers. You can get fully loaded quality (Beck-Arnley) for under $100.

You're putting a lot of nice work into those, and not trying to be a pessimist or anything, but frankly, I'll be surprised if those don't leak or chew up the new seals quickly. Hope it works out for you, though.

 

[fjgdk]

I've seen those pistons available aftermarket, if you're interested in replacing. But the cost makes it silly not to just buy remfg'd calipers. You can get fully loaded quality (Beck-Arnley) for under $100.

You're putting a lot of nice work into those, and not trying to be a pessimist or anything, but frankly, I'll be surprised if those don't leak or chew up the new seals quickly. Hope it works out for you, though.

Thanks on the pistons, but I got new Toyota pistons for about 9 to 11 usd per piston from ayamaya.com. I also got the oem seal rebuild kit and a 10$ tube of the toyota red rubber grease.

Just out of curiousity is your pessimism due to not changing out the inner seals (via splitting the calipers) since they arent available from Toyota ? Also, should I be concerned with the oem rebuild kit seals ? As long as the oem seals are properly and thoroughly coated with the red toyota grease (and the pistons as well) per the fsm, the weak spot in my rebuild per my view is the inner seals which are accessible only by doing the undesired - splitting the calipers.



The usd-jpy currency difference via ayamaya helps, but in the end I am definitely paying more rebuilding these myself. The reason I am doing a seemingly very illogical thing here in rebuilding vs buying rebuilt is because for other vehicles, all Hondas, that Ive owned and worked on in the past, the rebuilts kind of sucked and I've had to return them (some where beck-arnley I believe from autozone). One just didnt fit right at the install and I returned it and just rebuilt the cores I was going to donate (I think this was from Napa); another time the seals werent properly set or something and started leaking (these I believe were from Autozone). I got a warranty refund, got some from the junkyard and rebuilt them myself again.

 

[fjgdk]

Ready to rebuild...



The pistons themselves are wrapped in some sort of anti-corrosion paper from Toyota. I only opened one to check them and it is shiny and clean as expected. I wonder how "anti-corrosion" paper is made.

 

[Spike Strip]

My pessimism is from going through this procedure twice and they leaked, then just jumping to 4Runner calipers. Also, one of the local cruiser gurus said his experience is to just buy good reman's through a MUD vendor, like SOR, Cruiser Outfitters, etc ...

But since you've got the parts already (great price on those parts, btw) you've got nothing to lose but time.

I did not split mine as everything and everyone said not to. I replaced all the seals that were accessible without splitting the caliper. This was about 8 years ago.

I ended up purchasing Toyota Reman calipers and shipped they were a pretty good price. In this THREAD

Yes, difficult to find good remanuf'd parts these days. No experience with Honda stuff (until I buy a Fit! )

Let us know how it goes and maybe give some confidence to the next guy/gal

Oooooooo..... I LOVE that Toyota Rubber Grease! Kinda impossible to find rubber grease here!

I want.

 

[fjgdk]

[QUOTE="Spike Strip, post: 10938128, member: 9610"

Oooooooo..... I LOVE that Toyota Rubber Grease! Kinda impossible to find rubber grease here!

I want.[/QUOTE]


The Toyota Rubber grease seems to match the description "Lithium soap base grease" called for in the FSM to lube the pistons and rubber seals.

 

[Landpimp]

Put on few dozen oem reman calipers over the years, only issue is what you seeing on yours same reason as on mine, I didn't change the fluid often enough and my cruisers often sit for a bit.

Big quality difference between a parts store reman caliper and a Toyota reman. Bought 100's of reman Toyota parts and none have ever left me down.

My local toyota dealer use to(stopped 15+ years ago) rebuild calipers as part of a brake service, but the price (lower than ever) for new reman made that practice not cost efficient and I think they had less comebacks.

 

[fjgdk]

Put on few dozen oem reman calipers over the years, only issue is what you seeing on yours same reason as on mine, I didn't change the fluid often enough and my cruisers often sit for a bit.

Big quality difference between a parts store reman caliper and a Toyota reman. Bought 100's of reman Toyota parts and none have ever left me down.

My local toyota dealer use to(stopped 15+ years ago) rebuild calipers as part of a brake service, but the price (lower than ever) for new reman made that practice not cost efficient and I think they had less comebacks.

Regarding the poor state of the brake fluid, did you find it necessary to replace all the lines in the system from the master cylinder on down ? I want to do that but I also want to finish this front axle job and move the truck to a location more suitable for long term, "learn as you go" jobs (I am not a mechanic by trade and this is not my daily driver so I take ALOT of time to hopefully do things right ).

I have not seen fluid leaking from the hard lines or soft lines, in fact they don't look too mucked up except at the connections. How likely is it that, given that the fluid was not maintained right AND I've had the system open (plugged up at the wheels only with foam ear plugs) that I have great danger in not replacing ALL the hardlines ? Are the interiors most likely rusted and ready to chip away, potentially blocking fluid flow ?

 

[Landpimp]

Over the years I have replaced all the soft lines because they are 30 years old, no haRd lines beside the ones that go to the calipers.

I think most all my cruisers have had new soft lines by now, did all the fj40 last summer and the 45 wagon.

I just don't drive my stuff a ton and I kinda forget(got ADHD bad) when I changed(or not) brake fluid. It seems I go about 10 years per cruiser than its time for new calipers and wheel cylinders......which is really no big deal or a great amount of $. Yes....changing the fluid at least once in 10 years would help....

 

[60Works]

Its worth your time time go braided stainless on all the flex lines now. There's only 4. Bleeding these systems is sometimes problematic (especially trapped air in the master) and you don't want to have to do it twice. Braking is second only to steering in importance.

 

[Tin basher]

Wonder what the reasoning was for. The different size Pistons
I know on the 86 ifs trucks and 4runners the 4 cyl had the staggered piston size and the v6 had all large Pistons
Both calipers bolt on