I am having a hell of a time searching the Brake/Suspension section of the SC300/SC400 forum...

Car: 1992 SC300


The front calipers are seizing up after/during short drives (less than 10 miles and roughly 6-7 traffic lights) but after sitting for 2hours of sitting, they return to normal.

Symptoms include:
-Steering wheel shakes at speeds 25mph+ (but not always)
-Extremely hard to turn either of the front wheels by hand while jacked up off the ground
-Both front wheels are effected the same.
-Rear wheels spin free while both front wheels do not.


What I have tried:
-Lubricating the the slides on both front calipers
-Replacing all front pads (I do not remember how difficult the pistons were to compress with the C-Clamp, but I am about to go test one caliper right now)
-I removed the relays for the ABS and Trac earlier today. I have driven the car 3 times (a few hours between each time) and the symptoms have not changed.






A friend of mine told me to just replace the rubber sections of brake lines.

Any suggestions?

 

i had the same problem. tried everything from a new master cylinder, brake booster, and calipers. it ended up being a bad ABS motor that locked up the brakes on its own. i pulled the ABS relays(2) in the small relay box on the driver side fender under the hood. the car drove like there was no problems. 2 years later i have not replaced the ABS unit, because id rather spend money on something else for the the car and i know how to drive. ABS is annoying at times. the only thing is that the abs light is constantly on in my car but im used to it.

give it a try and see what it does. it cant do any damage to the car.

i have a 93 sc300 5spd with no traction control.

 

If you feel like you need to do a caliper rebuild rockauto.com has good prices on rebuild kits. It is a very easy DIY. Many people replace old/worn rubber brake lines with stainless steel ones. Russell SS lines are very nice quality. If you never did a DIY front caliper rebuild, Youtube has a nice series of "how to's" on the process. VERY easy diy.

 

I drove it once again, and the front brakes are still seized to some extent. I waited for everything to cool off and I took the driver side caliper off to lube the slides...

I could visably see that the boot on one of the pistons was out of place and ripped a little. The slides moved freely, but one of the pistons (the one with the torn rubber) was very difficult to compress.

I definitely need at least one new caliper, and I assume the other side is suffering a similar fate. I am heading down to the salvage yard to find some LS400 calipers, bolts, rotors and dust sheilds.


I will post my results after the LS400 brake swap.

 

Sounds like you may have a seized/frozen/rusted piston in your caliper. Possibly from water/moisture/dirt getting into your piston. Maybe time for a caliper rebuild or to use as a core on a rebuilt one. Remember if your doing a LS400 upgrade they must clear your aftermarket wheels, unless you currently have Supra wheels on your SC.

 

I am running 18x10 and 18x9.5 ROH DriftR wheels, so clearing the calipers will not be a problem.

 

.....I don't think there will be any problems.....sweeeet