can residual valves "go bad"?

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hotrod preacher

"Official RRR Chaplain"
Joined
May 8, 2008
Messages
3,486
Location
Newport AR
well let me give a few details of why i ask the question. My 46 ford has a underfloor mounted master cylinder/booster. Everything i read told me i needed residual valves to keep the fluid from gravitating back into the master cyl or giving a "spongy pedal" so i purchased 2- 2pound valves (one per front wheel brake line) and a 10 pound valve for the rear (drum brakes back there) the truck let me down the other day and it was a noise coming from the right front wheel--jacked it up and the brake was tight......and hot:mad:
after ALOT of tinkering on it-i have discovered by swapping the L & R front valves the problem moves with the valve.....

so can they go "bad"
can they be repaired
or what could have caused this scenario

any way, thanks for any input

HRP
 
I used the same set-up on my '53. They work, I think.

The check valve is probably just a ball that a 2 lb spring pushes on. It seems possible that a spec of dirt or metal could wedge the ball in the closed position. When you step on the brake the pressure would not drop when the pedal was released - keeping pressure on the caliper.

It seems more likely, however, that if the ball was wedged in one place either no pressure would get to the caliiper or the fluid would drain out of the master (and go where?).

Hope someone with actual experience has a better anwer.
 
the set-up has (1) 10 pound valve for the rear, and (2) 2 pound valves in the front =1 per side........according to what i've seen&read this is a common set-up and only one side has this "release issue" so it must be that one is acting different than the other.....

maybe i can take it apart and look at its guts and figure something out:p:rolleyes:
 
Yo HRP. I only use one for the front and one for the back, and have no problems. I have them right after the mastercylinder. You might try using your good one like that, and not have to wait?

PA41
 
I've been planning on installing some on my truck.

I think Tripper and PA are saying you should have them right past the MC - correct? Are you sure those are both 2LB on the front?
 
If one of the two valves on the front is actually a 10lb check valve it would make the disc brake drag. Only one 2lb valve is required on the front bakes and should be mounted as close to the master cylinder as possible. Also make sure it is mounted so the MC marked on the valve is on the naster cylinder side of the system. Good luck..[P
 
Actually I only have one going to the front, also. Both front and rear mounted within 12" of the MC.

HRP - you're not color blind are you? One (2lb) is red and one (10 lb) is blue or is it the other way around? Take that sucker apart and shoot some pics. It would be a good thing for us to know about.
 
Most underfloor MC's have the residual valves built into them. You sure you need the external ones?
 
thanks for all these comments guys.......
1st- the blues are 2 red is 10
as far as i've learned there is no danger of 2 running "inline" 2 2 pounders inline still only hold 2 lbs according to my research....
yes most only have 1 residual valve in front - 1 for the back, but once again (only what i've read) a 2# will give 2# on one or 2 calipers so 2 2# valves shouldn't be an issue--once again i have one side that works right...[S

i have a mastercylinder from a ford truck w/booster (maybe from an explorer)
and a prop-valve from a ford truck that has 2 inlets (for F&R of master) and 3 outlets (1 for rear drums 2 for the front discs) this is why i used 2 valves in these 2 lines

my latest thought tonite (while attending a kiddie pool party none-the-less) was to remove the disfunctional valve and try to "clean it out" with a brake cleaner.....worth a shot--and fairly cheap:eek:

while on this subject of braking....why couldn't i plug off one side of that prop. valve, using only one outlet to the front, and use only one residual, then "T" off of it to the L&R lines for the calipers?
or how about putting the residual valves in front of the prop valve?---between the prop valve and MC?

i really want to tear apart one of these residual valves and see what its made of either way[ddev
 
I have never understood why Ford used a prop valve with 2 front outlets. Ease of assembly is why Ford does most things, but perhaps they have a different bias because one side is heavier than the other (I doubt it). I would think you could plug one without any negative result. Could it be that something in your prop valve is sticking, not the residual valve?

I don't use the stock prop valve. It is not adjustable and more likely than not, I don't have the same weight bias as whatever it came off. The reason for using a proportioning valve is to be able to proportion the brake bias to the individual vehicle (or is it so they can sell more parts?).

I used an adjustable prop valve from Speedway ($45, I think) on the rear. It comes after the residual valve. In order to adjust it I have to crawl under the truck, but I figured I would only need to adjust it once.
 
Yes, they can go bad.

HRP,

I had one quit working on a 2# valve once, though it is unusual. I run a Ford master cylinder under the floor on my pickup and I put a single 2# valve about 8-12" from the master cylinder for the fronts. It locked my front brakes when it wouldn't release; funny thing was that when I bled the pressure off it worked as intended after that and I was able to get home. I replaced it anyway because I am paranoid about stopping. I was in the back seat of a '66 Falcon that had a brake failure once... never again if I can help it!

You could run a single, I still do and haven't had a problem since. I won't by cheap ones though, I try to get Wilwood if possible. My buddy runs their brake components on his Pro-Mod car running in the 6's and has never had a problem. That sold me on their products.

Batcave, most firewall mounted master cylinders don't have valves in them but make use of gravity and the proportioning valve to keep fluid where it belongs. As for my original '50 Ford cylinder, I could not find any evidence that is had residual valves built in.
 
stumped again

well my new 2lb resid. valve came in and i went today to get my 46 back on the road........
after putting the new valve on i still have an issue...swapped things around and done all i wanted to do in 100 degree weather...will go back tomorrow a.m. and see if i can figure out just what the crap is going on:mad:
'bout had all i want of brakes & brake problems....

i seriously think that with all my checking the other day i had it narrowed down to the valve-today it seemed like it was the prop valve....who knows........[S
 
FYI: The speedway prop valve is a wilwood prop valve with a sticker over the wilwood logo... I just got one a few weeks back and peeled off the speedway sticker to paint it black, and saw wilwood cast into the main body ;-)
 
Keep us posted, HRP!

This is good, fundamental, IMPORTANT stuff, which will, I'm sure, be of great help to many of us![cl

Totally NOT liking this hot, sticky weather either! Been close to 40 celcius with the humidity factor here for almost a month now.....After 1 1/2 after dark hours in the garage digging out tonight, Shea sez "enough, I'll finish it tomorrow!":D

Regards,
Shea:)
 
the residual valve was apparently the problem-i just had to get everything "bled-out" to make it all work right.....
"Chigger" is now on the road, and even legal w/tags and all.....
dropped about $50-$60 on gas in the last couple of weeks (no mile counter)guessing at least 100-125 miles -but think the brake issue has officially been resolved!!! (finally)

just for the record......brakes are NOT a place to cut corners/pinch pennies:eek:


HRP:cool:
 

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