Proportioning valve???

[JrZook]

Gday all,
I have a 85 drover swb, and just wondering if they do have a proportioning valve or just a 5 way joint. I have front brake probs ie the rears will lock but the fronts are weak. I have a new master cylinder, new rear cylinders/shoes, kitted the front calipiers/pads. Any suggestions would be great. Also i cant get a high pedal either. What other adjustments can i make??
Cheers Dan

[christover1]

Have you tried blocking off each brake line, checking pedal, until you know which end or which side problem is.

Looks like everything is brand new right through, so a faulty new part or air in lines is more possible.

christover

[muppet_man67]

there isnt propotioining valve on early models. I dont think zooks had them untill coilers. you can buy aftermarket ones fairly cheaply though.

[JrZook]

Have you tried blocking off each brake line, checking pedal, until you know which end or which side problem is.

Looks like everything is brand new right through, so a faulty new part or air in lines is more possible.

christover

Yea actually ive tried the block a brake line off thing, found on of the adjusters on the rear was out. How are these adjusters ment to be automatic? Wen they set them selfs they are still a heap out. Ive manually adjusted them to the closest clearance i can. Bit better brake pedal. When i block off both fronts the pedal is much stronger. Funny as u say a faulty part, as this is the second master cylinder ive put on. The first one was professionally 'overhauled' $$$ lasted 2 weeks till it leaked. I have a brand new one on it atm, could it to also be faulty? What else could i check. Is there any other adustments i can do to get a better brake pedal ie the booster pushrod??? Could the booster be sad? It still lasts for about 3 pumps after the engine is off.
Cheers Dan

[christover1]

The self adjusters can easily be put in backwards this was one problem I had when I still had rear drums.
They can bend and/or stick, too. I sprayed mine occassionaly with wd40.
There is also around 5 different shoe and wheel cylider types on rear of Sierras, none interchangeable, and not easy to spot the difference. Check against old shoes.

If blocking rear line didnt fix pedal, then problems at front.
The sliders can stick if they get mud/rust in them. Just clean, sand and graphite or grease etc.

Faulty wheel bearings can mimic brake troubles, especially at the front..The wheel/hub slop separates the pads, so pedal gets low..but usually pedal comes good after 2 or 3 pumps...air in lines, or a leak in lines can also mimic this...

In a nutshell I have nfi
But keep checking stuff and dont assume new parts are good, correct or fitted correctly.

My rear discs have paid me back double, in not having to replace shoes and wheel cylinders every 5 minutes.

christover

[christover1]

I dont have a power booster on a 1.0 litre, so dunno much about them...but a vacuum leak or faulty booster may be an issue??