Brake bias Valve/proportioning valve

[gazzahazza]

Hi All,

I have a brake bias valve fitted on my splitscreen van. It was fitted as part of an updated dual circuit brake conversion without a servo. It has gone faulty causing my rear brakes to bind. Details on this device are sketchy to say the least! Apparently they don't make them any more (unless somebody knows differently) and I haven't yet found anyone who can refurb them. There also appears to be few details on how to do a DIY attempt at a refurb. Anybody got any info that will assist regarding this component?

Cheers

GH

 

[Trikky2]

Have you tried bleeding it?

It has its own bleed nipple and is often forgotten when bleeding the brakes so gunge builds up inside.

Theres not a lot inside to go wrong since its a simple ramp and ball valve.

If bleeding it doesent do the trick then you can just remove and clean it.

Try a flush and shake first. If that still doesent clear it then it can be dismantled, though you will need to make a new gasket.

 

[gazzahazza]

Hi Trikky,

many thanks for the info, i assume that you have had a similar problem with thsi component. If so, what would you recommend for cleaning it? I have read a couple of articles on the web that suggest that you shouldnt use the bleed nipple (yes i was thinking the same, why put it there then?!). Also in terms of a gasket if i do dismantle it, is it a paper gasket as brake fluid and certain types of rubber dont mix as I understand it.

Cheers

GH

 

[dubdubz]

look here - I took one apart

http://forum.earlybay.com/viewtopic.php?f=4&t=23296" onclick="window.open(this.href);return false;

 

[gazzahazza]

Hi dubdubz,

thanks for the additional info. That looks straightforward enough, I will get out there over the next couple of days and give it a clean up. I have to say that mine was fitted at the correct angle and I can now hear the ball bearing moving inside, which i couldnt at first. Did you use a paper gasket to seal it when you reassembled?

Cheers

GH

 

[Trikky2]

Hi Trikky,

many thanks for the info, i assume that you have had a similar problem with thsi component. If so, what would you recommend for cleaning it? I have read a couple of articles on the web that suggest that you shouldnt use the bleed nipple (yes i was thinking the same, why put it there then?!). Also in terms of a gasket if i do dismantle it, is it a paper gasket as brake fluid and certain types of rubber dont mix as I understand it.

Cheers

GH

Done a couple. One worked fine after just bleeding it. The other I removed and put some panel cleaner in it and shook a few times, which flushed out the gunge and freed the ball bearing. (Blow out with airline and flush with fluid after to remove solvent)

I have no idea why people would advise others not to bleed it. It has a nipple on it for the purpose and it was put there because dirt, stale fluid and moisture can collect in there and not be flushed out by bleeding the rear brakes. This can form into a sludge and/or cause corrosion impairing the free movement of the ballbearing.

Yes the gasket is cut from thin gasket paper, though you might be lucky and find its stuck on only one surface. You can also use a very light smear of sealant (to make sure it doesent get squeazed into the unit) but chances are the clean out will do the job and save you taking it apart - like I said, theres not a lot in there - lol.