Evo 1 - Front brake lock up issue

[stealmy]

Hi guys,

I have a weird issue with my passenger side front brake. It doesn't want to retract and has locked up a few times now. Here's what I've done to try and fix the issue so far :

1) Both front calipers have been fully rebuilt with new seal kit by brake shop
2) Both front RDA slotted disks machined (Plenty of meat left)
3) New EBC Red Stuff pads
4) Front HEL braided brake lines fitted

So after performing all of this and bleeding all brakes over the weekend, I had the exact issue while out driving where the front right would not retract. Ended up heating the pad up so much it burt the red paint off, disk also looks worse for wear... but I managed to be able to release the brake enough to drive the 10 mins back home.

Anyone have any advice? might it be the brake distribution valve/combination valve fault as its only affecting the passenger side front?

I'm going to give the brakes another good bleed over the weekend and try again, before admitting defeat and taking the car to a brake place to get sorted out ($$$).

 

[evopwr]

Brake master cylinder faulty? do you have abs in your car? That could be another thing to look at.

 

[Hypo]

I thought these guys did a free inspection and report prior to completing any work.

Might be worth giving them a call.

http://www.autobrakeservice.com.au/index.php?id=50

 

[baza]

id say its the brake master cylinder

 

[Paul]

Prop valve. Located in the middle of the firewall just under the clutch master cylinder.

 

[stealmy]

thanks for the replies fellas. I was thinking if it was master cylinder it would happen on other wheels too. Will look into Prop valve, see if I can pick up a spare.

Hypo, I used to have a good ABS near me, but they got bougth out a few years ago and the new owners are crap.

If anyone else knows of a pretty good specilist brake place SE Melb, could they let me know. Dont mind taking the car in to get this fixed up once and for all - really shitting me I cant drive it!

 

[EVOCPE]

Could it be a blockage in the line from the brake master to that caliper??

 

[Hypo]

Could it be a blockage in the line from the brake master to that caliper??

It would be a strange blockage then as it would only be holding the pressure one way.

If the line can be bled and fluid is coming out than this can be ruled out.

 

[LWNSLW]

well it seems to have a blockage somewhere that's just enough to block the proportioning valve on the firewall, or it could be inside the abs unit??

 

[CYBORG-X]

It would be a strange blockage then as it would only be holding the pressure one way.

If the line can be bled and fluid is coming out than this can be ruled out.

it is not uncommon for a brake line blockage to hold pressure one way.
as you can imagine you have a vac assisted master cylinder to force the fluid one way, and only the tension of the brake caliper to force it back. if the fluid can push through the blockage, but not be able to push back your brakes will be applied on untill mechanicaly forced apart.

the old mini's were a real fucker for doing this, and would happen often... alot of mechanics rule it out if they bleed it and see fluid come through, but dont rule it out!!!

 

[pad4g63]

Have a look at the abs sensor on the the wheel that's locking up. I had a similar issue with one side locking up under braking
and all i did was clean the sensor on the hub and the drive shaft and it work.

 

[90xsi]

i also had the same problem. the abs sensor smashed the gears on my driveshafts for some strange reason.

 

[stealmy]

i also had the same problem. the abs sensor smashed the gears on my driveshafts for some strange reason.

hmm ABS sensor, I'll have a good look at that too on the weekend. Will bleed again and put a whole bottle throguh just to confirm no blockage also.

 

[cblancergsr]

if you pump the brake pedal till it locks up and then crack the line for that wheel on the master cylinder if it doesnt have any pressure at that line it should be a faulty master cylinder

 

[stealmy]

Bit of an update on this, still have the same problem. Had Goerge from J.G. Ozz come take a look last Friday, he rebled all the brakes, took apart and inspected everything. He had issues pushing back the pistons for the problem brake and has to use clamps.

Anyway, after rebleed and everything test drive of the car was OK. But then next day on the way to Southland, I had the same issue exactly. This time it seems the more pressure you apply, the brakes just lock to the point and do not return at all. Only way you can move again is through wear (it seems). I had a mofo of a job getting back home, but managed to.

So there seems to be a hydralic issue with returning brake fluid or something. It bleeds perfectly fine though - so seems to be one way. ont see how it can be the ABS sensors or anything like that. its a bit of a gradual thing, harder you apply brakes, the harder the clamp and will not back off.

Anyway, next stop will be a Brake place to have it all fully checked over, driving me nuts!

 

[90xsi]

keep us posted. ive got the same problem so i ended up just taking out the abs fuse and the car breaks fine. havent gotten around to looking at it as of yet

 

[stealmy]

keep us posted. ive got the same problem so i ended up just taking out the abs fuse and the car breaks fine. havent gotten around to looking at it as of yet

hmm will try ABS fuse out on the weekend and see what its like.

 

[stealmy]

ok, well pulled ABS fuse today and still have exact same issue (ABS light was on, on the dash). Went for quick fang around the block, then longer fang and brakes started to lock up again on front passenger side. So appears to be hydraulic issue now!

 

[Paul]

Im gonna take a stab in the dark here.

Is the caliper tightened properly to the knuckle?

Reason being, every time you push the brake pedal, the piston could be pushing the caliper back on an angle, forcing the piston out at an angle, therefore not allowing the piston to retract again.

I know, i know, unlikey but what else could it possibly be?

 

[stealmy]

Hey Paul, caliper has been removed a few times and checked now mate, last time by a mechanic last friday. I really dont know, but seems that fluid can not travel back at all - almost like theres a one way valve stopping it from releasing. weird issue...