First brake pedal stroke (1 Viewer)

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Well...I'm not sure what cured mine to be honest as I did several mods at the same time. FWIW the piston didn't look like it was the culprit but its ~$50 and easy enough to replace if you follow the leader on this job...Skidoo's excellent DIY thread on same.

So back to what I changed: I installed the new piston/plunger, installed the Stoptech BBK (front only...still running my NAPA rear calipers without issue) which has its own calipers. I, after this work bled the system like I always have done but just for grins took it to our dealership for the full SST bleed out (first time for taking to the dealer for bleeding of the brake system). FWIW I couldn't tell any difference pre/post dealer bleed out. So the problem I had was either at the piston-plunger level or the front calipers. The front calipers were not frozen when I removed them BTW.

So...I suggest you install the new piston-plunger and do a good bleed out. If the problem still persists I'd focus on the front calipers.
 
I'd put my money on the MC piston and seals!
 
So back to what I changed: I installed the new piston/plunger, installed the Stoptech BBK (front only...still running my NAPA rear calipers without ....

I was looking at the StopTech BBK. Is that a big improvement and worth the dough?
 
From my perspective the Stoptech BBK is worth every penny; 110% satisfied ;). Let me qualify that statement: Aside from when my '99 100 was stock/relatively stock I was less than enamored with the brake performance of my 100. Post Stoptech BBK, now with over 30k miles on them, I am done wanting for better brakes. Done.

Stepping stone: Between the OEM and the Stoptech BBK system I discovered ART cryo'd rotors and Porterfield carbon/kevlar pads. This set-up helped by increasing: Peak power and rotor life (currently >100k miles on my rear ART rotors) but modulation was lacking when the peak power turned on. Also my pedal free play, something Stoptech said would occur, is about 1/2" and from there its very solid with super foot to rotor 'communication' for the driver.

My rig in full explore mode is right at 8,000lbs (dual fuel tanks full, ~25 gallons on board water, food, dog...you get the picture) and the brakes were IMO woefully inadequate for emergency stops & some steep off-road trail descents.

You will, however, have to run 18" or larger wheels to provide clearance for the larger system. After searching around I ended up buying the BBK kit from LPI Racing. They were about $300 less and they have top notch service.

Hope that helps you.
 
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From my perspective the Stoptech BBK is worth every penny; 110% satisfied ;). Let me qualify that statement: Aside from when my '99 100 was stock/relatively stock I was less than enamored with the brake performance of my 100. Post Stoptech BBK, now with over 30k miles on them, I am done wanting for better brakes. Done.

...

You will, however, have to run 18" or larger wheels to provide clearance for the larger system. After searching around I ended up buying them from LPI Racing. They were about $300 less and they have top notch service.

Hope that helps you.

Thanks it does --. I definitely want better brakes! I guess the required upgrade to 18" was lost on me when I was researching the BBKs. That puts the project down the list a bit. I'll try the MC rebuild route first and see what that does.
 
For your first stage would recommend the MC rebuild along with a set of Hawk LTS pads. I have been very happy with them. If your rig is not far behind spressomon's 8,000 lbs try the Hawk SD pads, and if you drive as hard as him, start saving up for that BBK.
 
For your first stage would recommend the MC rebuild along with a set of Hawk LTS pads. I have been very happy with them. If your rig is not far behind spressomon's 8,000 lbs try the Hawk SD pads, and if you drive as hard as him, start saving up for that BBK.

Thanks Skidoo -- no, I'm not loaded yet, and quite stock for the next month or so, but all of my mods are in process, so it wont be long before I strap my RTT and my whole family into this thing. I'm not a big fan of the current braking power. I've developed the two-push-two-step to get good braking when i need it, but that's ridiculous. The fact that Toyota says its normal for "big heavy trucks" is also ridiculous.

So from what I gather, the dealers don't want to do just this MC plunger repair? I am a couple of banana guy, but brake fluid jobs make my bananas slip!

I'd like to find someone nearby to NC who has done this before, so i can at least have a mentor!!
 
Understand concerns over jumping into brake system repairs. My rig is pretty modified and expect I am pushing 7,400 lbs for long expeditions and with the LTS pads, brakes do everything I ask of them, no two-step dance required. MC rebuild should help you hang up the dancing shoes and the pads will help with the extra weight.
 
I concur with bluecruiser - I had this symptom on my '99 for a number of years. When needing to brake, I'd kind of pump the brake once, then the second stroke would feel normal. Then from a full down-pedal position, use the left foot to help the pedal return back to the normal up position. Very irritating but I just learned to live with it.

Toyota dealership wanted $2700 P&L to replace the master cylinder and booster assembly. ouch!

Last summer, bluecruiser was kind enough to help me with the Master Cylinder Rebuild Kit (ok, it's just the piston) that was about $50. Followed the write-up here on the board, took about 5-6 hours in total if I recall.

BEST THING I've ever done to the truck! Almost a year later and works like it SHOULD - firm pedal and braking on the first pedal down, don't need to pump it first and no more left foot return assistance required.

I think the issue is this little black plunger at the end of the piston - we noticed that on the old one when you pushed it in it kinda stuck and didn't return by itself or right away. The new part did.

My .02 anyway.
 
I concur with bluecruiser - I had this symptom on my '99 for a number of years. When needing to brake, I'd kind of pump the brake once, then the second stroke would feel normal. Then from a full down-pedal position, use the left foot to help the pedal return back to the normal up position. Very irritating but I just learned to live with it.

Toyota dealership wanted $2700 P&L to replace the master cylinder and booster assembly.

My .02 anyway.

Wow, I'm glad I don't have the return pedal issue <yet>... I just really don't understand why Toyota won't do this simple and inexpensive repair and subject people to multi-thousand $$ replacement of the whole assembly.

This is straight up next on my list to do next... Would really love a mentor in NC! Any takers?
 
Well.... Had a total brake system issue today. Lower than usual pedal and then intermittent ABS/Brake/Buzzer for about 10 seconds every 4th or so brake push. After going to a side road and doing some test stops, the pedal went to the floor once and now feels like I have a stuck brake caliper.

I had been contemplating having a local Toyota specialist do the MC rebuild, so I went over.

He just called and said there is stored code for C1256 a "Accumulator Low Pressure". From my readings here on mud, seems like I'm headed for a new booster/motor assembly at a minimum and perhaps a full MC. The Specialist said he couldn't do it and it would have to go to the dealer for further analysis if it was either just the accumulator, the MC or the ABS pump or all of it together.

Any words of wisdom? I'm reading there is a chance if it's just the accumulator (maybe the motor) there is a part number for that and likely that can just be that. Given the soft pedal history, should I also do the MC replacement too?

Not really looking forward to shelling out the dough for the MC and Accumulator.

It really does seem that this is a plague on the '99s
 
MC piston replacement cost is almost insignificant relative to replacing the entire MC/booster system...especially if you're slightly handy and can follow Skidoo's valuable thread on same.

IIRC the plunger/piston was ~$50 when I did mine a few years ago.

I would also be 100% certain you don't have one or more sticky/partially returning/non-returning calipers. Code(s) aside this will give a similar pedal symptom.
 
MC piston replacement cost is almost insignificant relative to replacing the entire MC/booster system...especially if you're slightly handy and can follow Skidoo's valuable thread on same.

IIRC the plunger/piston was ~$50 when I did mine a few years ago.

I would also be 100% certain you don't have one or more sticky/partially returning/non-returning calipers. Code(s) aside this will give a similar pedal symptom.

I've had this into the dealer and another specialist four times and they have only found frozen guides once. They rebuilt the guides on the right rear and then I had good pedal feel, but that was back in March before I drove cross country. Some where on the way back I got the low pedal and double pump issue back. Since then I've had them look 3 times and nothing.

I was fully ready to do the MC rebuild kit until yesterday when I started getting ABS/Brake warning and even lower pedal feel.

Are you saying that even the piston issue could cause the accumulator low pressure code?
 
I can't offer expert/experienced advice whether or not the piston can be responsible for the accumulator low pressure code. I was merely suggesting if you go to the trouble and expense to replace the MC/booster I would also include a new piston in the mix. Hopefully Skidoo or others more experienced in this department will chime in with their thoughts.

You've probably already read my posts about my experiences with the low pedal and double pump issues I had with my '99 for years. I can only offer after I replaced the front calipers (BBK) and did the new piston swap at the same time I've completely and fully eliminated the low & double pump pedal issue. Like you/your mechanic I replaced caliper/pad guide pins prior to the BBK and piston swap, but can't verify if I had a sticky caliper piston puck or not; however I have my suspicions. I believe the caliper design apart of my Stoptech BBK system is responsible for the very high and very firm pedal feel. However I don't think the same parts have anything to do with the lack of air and/or misplaced brake fluid in the system.

And given no one to the best of my knowledge, Toyota/Lexus certified mechanic or otherwise, has offered a real explanation of the cause for this fairly common brake issue symptom amongst early model year 100's I don't have the highest level of confidence in same...its always a bit easier to cover your bet if you just swap out all the parts...and the most expensive parts at that. Great for the parts counter and service department #'s...not to mention some commissioned mechanics incentive to expand both parts and labor costs for their own benefit (not unique to just mechanics of course...).
 
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I can't offer expert/experienced advice whether or not the piston can be responsible for the accumulator low pressure code. I was merely suggesting if you go to the trouble and expense to replace the MC/booster I would also include a new piston in the mix.

You've probably already read my posts about my experiences with the low pedal and double pump issues I had with my '99 for years. I can only offer after I replaced the front calipers (BBK) and did the new piston swap at the same time I've completely and fully eliminated the low & double pump pedal issue. Like you/your mechanic I replaced caliper/pad guide pins prior to the BBK and piston swap, but can't verify if I had a sticky caliper piston puck or not; however I have my suspicions.

Thanks for the feedback. Gosh I would hope that the piston is replaced if they end up saying I need a whole new MC unit!! Now I'll make sure I really understand what they are recommending... Currently sitting a the dealer waiting to hear their thoughts.

Yes, I've read yours and Skidoo's threads over and over and over trying to diagnose this issue.
 
So, the dealer is saying i just need the accumulator/ motor assembly (47070-60010), and that it doesn't require them to pull the MC. So i asked about doing the Piston rebuild and they say there are not instructions or recommendations to do that at this time. (of course there are instructions here! and the FSM shows the parts)

Should I force the issue while they have things apart, or see what happens when they get it all together?? I really hate having to go back and pull the MC if this isn't the only issue!!

EDIT: I forced the issue, told them the Piston Kit Part number and page BR-63 from the FSM. They agreed and said it would only be an additional hour of labor! Thanks MUD! Without all of this background, i wouldn't have enough background to make an informed decision.

Not fun to spend this much money, but at least as much of it that has bad history here will be addressed! Will advise after I pick the truck up.
 
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Wow, I'm glad I don't have the return pedal issue <yet>... I just really don't understand why Toyota won't do this simple and inexpensive repair and subject people to multi-thousand $$ replacement of the whole assembly.

This is straight up next on my list to do next... Would really love a mentor in NC! Any takers?

Although not a near trip for you just know Onur aka beno here is in Atlanta and will get OEM Toyota parts at a substantial discount/savings shipped out to you. And he does LC wrench work, again, at considerable savings. Send him a PM to inquire...maybe he travels dunno.

Disclosure: I have consumed tekilla with him on occasion...and harass him any chance I get :D
 
Although not a near trip for you just know Onur aka beno here is in Atlanta and will get OEM Toyota parts at a substantial discount/savings shipped out to you. And he does LC wrench work, again, at considerable savings. Send him a PM to inquire...maybe he travels dunno.

Disclosure: I have consumed tekilla with him on occasion...and harass him any chance I get :D

Yes, have gotten parts from Beno before... my local dealer gives our LC club a pretty good discount on parts and labor, so I'm going to let them handle this one turn-key.

Hope to have some tekilla with both of you guys one day...
 
Cboyd, do yourself and your family a favor. Invest in a new aftermarket MC if you don't want to buy an original one.
I know they're less than 200 if you visit any website that sells aftermarket parts.
avoid the rebuilding yourself route. Please.

then let us know what the results are. good luck. :)
 

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