Globalinx

Have anyone have had this problem?

I recently got a set of freshly rebuilt 4 piston front callipers for my car. After going for a ride and driving hard on them, I lost 50% of pressure in the brake. When I came out of the car I saw smoke coming out on both sides. I thought they just got hot, but after closer inspection I noticed brake fluid dripping on to the rim. I thought it could have been a loose line. When I took the wheel off, the line was fine. The fluid was coming from somewhere inside. Is this a normal occurrence for LS callipers if you push them? Do piston seals blow regularly? Could it be the seal between the calliper parts? Anyway, I towed the car to the shop that installed them and won't know the verdict till Monday. I never had anything like that happening to any of the brakes in any of my cars in the past 14 years. And I have been driving cars on race tracks with stock brakes for years now, and never had any problems aside from premature brake softness due to high heat.

LiCelsior

iTrader: (32)

the person who rebuilt them didnt do it right. the LS calipers have 4 pistons so its bound to mess up when someone carelessly rebuilds them. if ur car savvy and have access to a air compressor, its not that hard.

same concept as this, http://www.lexls.com/tutorials/brake/fbcaliper.html

deanshark

You might have went too hard too quick. Or, someone didn't "rebuild" them correctly or with the correct parts and seals. They're under warranty, right? Hope they fix it right for ya this time. Out of my 35 years of driving, and the over 20 cars I've owned, I've only had 1 caliper freeze up on me. (91 Grand Prix) I never really had any brake problems over the years, thankfully.

billydpowe

iTrader: (1)

Is this a normal occurrence for LS callipers if you push them? Do piston seals blow regularly?
I recently got a set of freshly rebuilt 4 piston front callipers for my car.

do a search... and see all the fussing about blown calipers.....

a hint to the wise is sufficent.

Globalinx

OK I did a search on word "Caliper", and "Calliper" going back to 2006 on LS400 forum. No Info! I think 1 guy had an issue, and his post didn't contain any details.

Does this show that its a somewhat seldome problem- Perhaps
Did I get an answer for: "if I can push them"? -NO
Was your "Use a search button" post useless and a waste of mine and yours time-YES

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PureDrifter

iTrader: (10)

lose the attitude.

so you're saying you searched and didnt find much/anything about a similar situation to yours?

well suffice to say it isn't a common issue and you just got a shoddy rebuild.

LiCelsior

iTrader: (32)

i was going to tell u to search also but felt like being nice in that post. but u obviously didnt read it and use that information.

Globalinx

Hey, I appreciate your input. I read your post, and thanks. It's just I usually use search button before asking questions. And if I do not find the answers, I ask them here. I am sick of people posting replies without any added value or an answer to a question like the other guy : "use search". I did a search yesterday and found no answers, so after a "search button" post, I figured that I had missed something, and had to look through all the treads today again. Again no value!

Ok. Enough of my venting.

I should probably rephrase my question. Does anyone successfully run 4 piston LS400 callipers under high load on the track. I had replaced and put the LS callipers on to my GS400 which I take to a track once in a while (road course). My stock GS came with 2 piston brake system, which would heat up fast and loose the grip, but never had a blow out. Now, some guys on GS forum said to bolt the LS brakes for better stopping. Blew them on the second lap. Any suggestions?

PureDrifter

iTrader: (10)

perhaps searching in the GS forum....

nine3es

iTrader: (3)

rebuild the calipers correctly and mic your rotors, make sure theyre in spec. for the new calipers. if your rotors are too narrow, the caliper pistons will over-extend causing failure.

Globalinx

This is how I ended up here. I got the idea from the GS forum to change the brake system. There is only a handful of people with LS brakes on their GS cars. Hoped to gather information from the actual drivers who had LS brakes by definition as I would be exposed to a larger audience with LS brakes. And here is a problem. Most GS cars with LS brakes are show cars, and I don't think many people track their LSs ether.

RA40

iTrader: (6)

The usual Toyota disclaimer about street use and not under racing/track conditions.

Given that many of us have stop-go countless years without issue, my suspicion is that some seal was out of spec and failed under the heat and increased use. Get them rebuilt using the Toyota OEM spec parts and take it back out. While none of us wants to experience a braking failure, if it does not hold up again, it would deem these as incompatible under these track scenarios.

Did you take a caliper or rotor temp reading? This may also lend additional info under the heat which the calipers and rotors are having to operate under. A next time situation so you have some data to go by. Granted the rotors and calipers will dissipate temps so getting a peak reading will be more difficult.

I'd also check with the Supra guys for any additional experiences. The Supra caliper might be a consideration.
Otherwise, calipers with a known rep for your tracked car.

sdls

not long ago, rockauto had a beck/arnley ucf20 brake caliper kit for $8.00, it was a rebranded Japanese kit and was absolutely top quality

steve2006

Sounds like either a bad rebuild as others have said or you exceeded the operating conditions for the brakes,did you install suitable pads/discs for racing,suitable fluid for racing?

This link may help.

http://www.lextreme.com/suprabrakeupgrade.html

sethjon

There is no "pushing" a caliper. Either it works right or not. If the lines are not leaking the seals must have been installed improperly. I would give the guy that did them a piece of your mind. You could easily have been killed. When it comes to brakes you don't rush a job and THOROUGHLY check to make sure its right.