Thing on firewall for the brakes

[Damkid]

How important is this thing? and what does it do? i'm still trying to rule out whats wrong with my brakes and if this thing isn't important i'll just bypass it so there's less to diagnose (even though theres only 2 things i'm looking at that could be wrong)

[packrat427]

Pretty sure that is your proportioning valve , if you took it out , I think you would have too much pressure going where it shouldn't .

[Damkid]

well i'm just thinkin with how my brakes are working in diagonal pattern, (only front drivers and rear passenger) maybe this is whats wrong with them

if i took this part out, i'd have it set up so the front line (or back whichever puts out more pressure) from the M/C runs the front brakes and the opposite line runs the rear brakes

this picture is of my spare from my parts car, so i'm just looking for more info before i do anything with it, if worse comes to worse i'll just install my spare

[av8ter]

It is the metering valve. If you replace that piece on you car it will fix it. There are 2 areas to which the brakes are applied, front right-back left, front left-back right. Replacing that part should be the fix!


Kevin

[jglutz]

Once in a while when doing car repair it's fun to play the game..."Who's the Fool?" The factory fo putting an un-nesscary part in the car? Or me for taking a necessary part out.
The proportioning valve is very critical to brake operation. First and fore most if one brake were to have a catastrophic failure....at least the two brakes on the opposite diagonal will still function provided you're not out of fluid. Secondly, for the brake force to be properly applied/balanced, the proportioning valve reduces pressure to the rears.

Without the valve installed..a failure at one brake would lead to total brake system failure (if a rear cylinder fails don't expect the hand brake to work, wet pads). Also with out the valve you are risking rear wheel lock up. What is the actual problem you're having?

FB71 WHERE ARE YOU?

[FB71]

ight here, Sunshine.

Its a combination valve, proportioning and metering together. Notice the two pots at the top are labelled 'R' fo rear, the two pots to the side are labelled 'F' for front, and the two ports facing the camera come from the master cylinder. If I remember correctly, the rears cross outside of the valve. So, chances are that one side of the combi valve is plugged with nastyness. Please, please, PLEASE, replace it with another one. jg's description of its operation, and the follies of operating without it, are accurate.

[FestYboy]

jim, couldn't another solution be that the half of the master that supplys the non-working corners isn't providing pressure/fluid volume and therefore not opperating the brakes on those corners?

just a thought...

[monkeyracing]

Please tell us you're kidding. You'll need that to live.

[Safety Guy]

Damkid, have you checked out your M/C? My car had those same symptoms and that's what it was.

Karl

[FB71]

FestYboy, yes it could. I wrongly assumed he had already checked the MC. My bad.

[Damkid]

Please, please, PLEASE, replace it with another one. jg's description of its operation, and the follies of operating without it, are accurate.

this is the info i was looking for, i basically wanted to know what it did so i knew whether or not to bypass it

so after reading all the info, i will be replacing it, not bypassing

Thanks for all comments

[Damkid]

FestYboy, yes it could. I wrongly assumed he had already checked the MC. My bad.

i had replaced the M/C in February 07' with a used one, so i'm assuming it's good, but it's used, so since i have spares for each parts, i'll replace one, bleed the brakes, and see what happens, if the brakes are still crap, then i'll replace the other one