AE101 FxGt Brake proportioning valve

[rolla_fxgt]

whats the easiest way to get at it to get out to be serviced? is it easiest to drop the sub frame out? or is there an easier way

[Lloyd]

Easiest way is to not go to VTNZ

Was it both service and park brake out by lots, or just one of them?

[rolla_fxgt]

service, its def out, just had it in at Sims, they said its in right at the bottom of the fire wall, just thought taking of the exhaust or sonmething would of been easier. basically just asking if I was getting ripped

[rolla_fxgt]

Easiest way is to not go to VTNZ

I was a bit suspicious that their machine was out as they failed 2 other cars for brake balance out well I was there

And I'm never organised enough to book a warrent, so its easier to go there

[soopachargen]

will getting them really hot work in this case?

[mjrstar]

i did this on my girlfriends ae111r corolla and it was a matter of attacking it from both the top and the bottom i took the intake pipe off from the throttle body and this gave a bit more room to reach under the inlet manifold.. what a pain in the @rse place to get to.. i think it was around $200 to get overhauled as they a sealed unit...

[rolla_fxgt]

i did this on my girlfriends ae111r corolla and it was a matter of attacking it from both the top and the bottom i took the intake pipe off from the throttle body and this gave a bit more room to reach under the inlet manifold.. what a pain in the @rse place to get to.. i think it was around $200 to get overhauled as they a sealed unit...

Cool, they quoted me 230 to do it and recondition it, so not a bad price.

Taking the intake off sounds like a pretty good idea actually, though I can imagine its still rather fiddly to get at

[neo]

Really, a failed prop.valve.. sounds wierd (you have checked all the pads and bleed all the fluids I assume)

I'd just get the 2nd hand one off Santa's 20v fxgt

[rolla_fxgt]

Really, a failed prop.valve.. sounds wierd (you have checked all the pads and bleed all the fluids I assume)

I'd just get the 2nd hand one off Santa's 20v fxgt

Yeah that's the thing everything else has been checked, and everyone says its weird for it to go.

I've just come to the conclusion that my car is possessed by a gremlin that makes it break really random stuff. Either that or it was the only car Toyota has put together badly

[Mr Revhead]

yeah its not at all uncommon for the prop valves to get a bit jammed up if fluid changes have been neglected

[rolla_fxgt]

right so rebuilding the prop valve only brought it up a bit, and now they're scratching their head to what it could be, any bright ideas from the toyspeed populace? New discs?

[mjrstar]

the first thing to figure out is one high or the other reading low. when mine failed i thout one side was weak but as it turned out the other side was getting unrestricted flow and was reading high... silly me i did the cheapest stuff first, shoes and slave cylinders etc..
if one side is low it has to be something reducing friction. glazed pads, sticking slave cylinder, fluid blockage or other part seized brake mechanisim.
if it is the other side reading high it can't be much other than the preportioning valve unless the disc/drum was scored and produced more friction, or soething was stopping the wheel from rotating freely.. (such as a partially seized wheelbearing) but i very much doubt this is the case...
maybe posting up what the braking figures were on each brake (front and rear) would give us a better idea.

[neo]

To put things straight

What is the problem? Is it the front / rear split? Pulling to one side or only one wheel not locking up?

...
This car has rotors front and back

I assume the following list has been completed
All lines bleed out fully, and in the correct order
New quality brake pads front and rear
Floating Caliper sliders removed, greased and replaced
Brake Pistons push in/out without restriction, no surface rust on the pistons
No damage to any of the hard or flexible brake lines anywhere
Hand brake mechanism has no issues

[Alex B]

Nah, VINZ failed him on a wof. Hence, you dont go to VINZ.

[rolla_fxgt]

yeah its the left/right rear brake balance out, sorry should of made it clear left 180, right 90, not sure on the new figures(post prop valve rekit), but still not enough to pass. Handbrake is fine 140L, 130R and so are fronts 240L 260R

All the pads have been checked and have minimal wear (just over a year old), callipers show no signs of stickiness, unsure about the sliders, but pretty sure they've been checked, along with all the lines (I assume a brake specialist would check this and the sliders), they're going to check the trueness of all the discs tomorrow, but I'm pretty sure they're straight.
Also as far as I'm aware they did a full bleed on the brake system with new fluid.

Only thing I could think of it being something to do with the handbrake adjustment? Are they self adjusting each side, if one was adjusted fully in and the other out, could this cause an imbalance?

[Bling]

I've had a sticky piston before which caused balance issues.

I've also just sanded the pads and discs before and had a recheck and it pass fine.

How old are the discs? Or did i miss where you said they are newish?

Perhaps take off the brake bleed nipple on the right side rear and flush some fluid through, might have some shit stuck in the line after the prop valve? Something in the line could reduce the pressure to the brake.

[neo]

OK something really simple, who ever it is, wound the piston in/out to suit the wear on the pads eh?

[rolla_fxgt]

OK something really simple, who ever it is, wound the piston in/out to suit the wear on the pads eh?

nope that wasn't it either, both calipers have just had new seal kits, which has swapped the pressure round the other way, and then it came back when the discs were swapped over.
Both the specialists & I are now really confused. Anyone ever seen this happen before?

[rolla_fxgt]

I have no idea why, but new pads sorted it, even though the old pads looked mint.

[jondee86]

Had a similar problem when I had the rear pads out of the 86. Got
mixed up when I put them back, and finished up with one pad that
didn't seat properly. The car pulled to one side under hard braking
and I couldn't figure it out. Tried all sorts without success.

Turns out that the face of the pads wear on a slight angle. By swapping
them round I got one that was only making contact with the disc right
on the end of the pad. Only picked it up when it wore down far enough
to start showing a contact patch.

New pads would have solved that too

Cheers... jondee86