ae101 rear brake balance

[krock]

hi, my car (ae101 fxgt) has a large imbalance between rear brakes, mechanic has suggested that it is probably the brake proportioning valve as these fail fairly regularly on toyotas, or maybe it was corollas in particular.

From what i gathered the disks, calipers and pads were ok as he didn't find any problems with them other than a bolt which was missing on a caliper and he replaced for me.

can anyone back this up? a) that this could be likely cause of imbalance, and/or b) that this is a common problem...

Cheers for any help

[Lloyd]

Yes and yes. You don't trust your mechanic?

[Bling]

Yes and Yes.

[strx7]

there was a thread about these 7-10 days ago

[krock]

thanks for the help

[rollaholic]

send valve to yems for rebuild, way cheaper!

[krock]

ok, i'll ask him . cheers

[allencr]

Is there actually valve between the LR and RR brakes or just a T?
If it doesn't have a problem between the F & R where the valve is plumbed in, then it isn't a valve problem!

***
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[quote=Matt Dunn]Almost all FWD cars are split diagonal braking systems, [/quote]

Thanks, news to me, except for what Volvo's been doing for 40 years.[/b]

[matt dunn]

Is there actually valve between the LR and RR brakes or just a T?
If it doesn't have a problem between the F & R where the valve is plumbed in, then it isn't a valve problem!

Almost all FWD cars are split diagonal braking systems,
so the LR and RR are not connected at all, there is not a "T" as you say,

and from my understanding they kinda have two valves, one for each rear wheel, so one can jam and you get too much brakes on one rear wheel, although both thye valves are built into one unit.

[Bling]

Do cars with ABS use the same valves?

eg ae111 abs
ae111 non abs?

[matt dunn]

Do cars with ABS use the same valves?

eg ae111 abs
ae111 non abs?

I would presume so as you still need the same bias with abs,
otherwise the abs would kick in to stop locking the rears everytime you braked.

[TRD Man]

Old Toyota brake hoses (about the age of AE101) have been known to collapse internally causing a blockage which will effect the balance.
It is far easier, and less costly, to check this before the proportioning valve.

[rollaholic]

there are also two types of P valves, one with an alloy hosing and i believe 5 inlet/outlets and one with a cast housing and only 4

or something like that

[krock]

Old Toyota brake hoses (about the age of AE101) have been known to collapse internally causing a blockage which will effect the balance.
It is far easier, and less costly, to check this before the proportioning valve.

apparently i have a "cracked" rear brake hose, i havent checked it out yet, and im not sure if it could be cracked and not be leaking, but maybe that could be connected with my imbalance and not the prop valve...

[rollaholic]

the outer sheath can be cracked or perished from age / heat etc with the inner section retaining its integrity, for now at least.

[krock]

yeah ok. so could be either/or then. have to try one first then.