alright, so i was cruising the information superhighway, and came upon this diagram.
now, this image shows that the proportioning valves (for the front/rear) are located right in the master cylinder. from there, it goes out to the abs unit. Now, the MC casting seems to be a little bit different for the earlier abs unit, versus the newer abs units (like in my car), but overall, the MC seems to be pretty similar.
so, this said, could it be that the proportioning valves (if any) would be located in the MC? if so, then we go back to the original question, are those two things on the rear lines residual pressure valves and NOT proportioning valves? further proving that yes, josh dearman is correct about those being 10 psi rpv's. and that they should be changed out to 2psi valves. or more debatedly, completely removed.
only to confuse more on why some jbodies have them (regardless of year), and others dont?
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- Sold my beloved J in April 2010 -
My 2000 service manual calls them proportioning valves... as seen in your picture. They are not found on 95-99 cars, only 2000+ ones. Dunno about 03+ non-ABS cars... but definitely were NOT on my 99... I swapped brake lines to the 2000 style when I swapped the ABS unit, to convert from 99 to 2000 wiring (for the supercharger) on the white 'vert.
so josh says
Joshua Dearman wrote:I installed the neon calipers and brought them up to pressure while off the car...( a piece of wood substituted for the pads and rotor)....when I let off the brake and removed the wood, much to my surprize the caliper piston was sliding out surprizingly fast. Almost too much to hold back by hand...proved that without replacing the valves, brake drag would be certain. Not much given the emense pressure required to stop, but drag none-the-less.
Anyway, I bought some Disc brake 2psi valves and replaced them and all is good, no slide on the repeat test.
interesting eh? lenko if you have aim, im me mang.
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- Sold my beloved J in April 2010 -
now, i also just found this on this website
http://www.babcox.com/editorial/tr/tr59940.htm
and i believe the info, because i remember a LONG ass time ago this same exact subject came up and someone referenced the same stuff on this site. anyway, most importantly is
Quote:
This fall, the new DBC-7 system will also be added to the 2000 model year Chevrolet Impala, Monte Carlo, Malibu, Cavalier and Venture, Pontiac Sunfire and Montana, and Oldsmobile Cutlass and Silhouette .Something you won't find on a DBC-7 equipped vehicle is a brake proportioning valve. DBC-7 uses the ABS solenoids to reduce pressure to the rear brakes during normal braking to maintain proper brake balance. This is done by monitoring front and rear wheel speeds, and reducing pressure to the rear brakes as needed when there's a difference in wheel deceleration rates.
so, this could assume why the MC also changed a little bit, and maybe there are no prop valves in the newer ones. so then, again, are those "things" that gm calls props really rpv's? .......
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- Sold my beloved J in April 2010 -
Got me... but seeing that no one has had any problems actually putting the brakes on (either Neon or Fiero or Camaro or Corvette) and actually using them, other than a test with a piece of wood....
I'd say you're all reading too much into this
it's just brakes
but what begs my curiosity is that people (including weas on his newer vehicle) have said that there was more dust on the rear rims. meaning, that it is possibly dragging, cuz of that. this is all just interesting
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- Sold my beloved J in April 2010 -
Got me... I never had that problem.
I've got those on my car. I don't think there's much testing I could do for you to find out if they are props or rpv's.
I'll be putting in Josh's rpv's when I get ready for the swap.
Desert Tuners
“When you come across a big kettle of crazy, it’s best not to stir it.”
ive got the baer copy rears on my g/fs 02 cav , and my 00 cav
and i havent seen any dust on the rears , of either car
maybe its the pads others are using that are creating the extra dust
Originally I was getting a LOT of extra dust due to my ebrake cable not being properly adjusted.
I swapped to low-dusting pads and properly adjusted the ebrake assembly though and haven't had an issue since. Though I believe my rear pads are wearing a bit quicker than I'd expect them to.
Had the SSBC kit on the rear of my 96 cav for 4 years, never needed to replace the pads and never had a dust problem. Just replaced the pads when I reduced the size of that kit, not because they needed it but because I wanted new pads witht he new rotors. They still had about a year left in them, so obviously I have never had a problem with brake drag after 4+ years. Like John said, some people are just reading way too much as many have never had a problem but someone comes on saying it could be & that they sell the valves & suddenly it's a problem & the fad is to add them to systems that work without them on many cars for many years...
I think you misunderstand. If it's an issue, then the solution would be to remove them. Not to add anything.
Lol nah just enjoying the rum a lil too early on a tuesday night & typing way too much
Me too. No issues here with my rear discs brakes, until now.
Regards,
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Eliot wrote:Me too. No issues here with my rear discs brakes, until now.
Regards,
Hey Eliot!!
Doesn't this whole conversation just bring on the nostalgia??
Wild Weasel wrote:Eliot wrote:Me too. No issues here with my rear discs brakes, until now.
Regards,
Hey Eliot!!
Doesn't this whole conversation just bring on the nostalgia??
Yes absolutely.....
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ELIOT. Now.....boosted.
my friends 98 zed has them, i have yet to look under my 98 cav
1998 Chevrolet Cavalier
5-spd
