what is the purpose of the proportioning valve?

15

Asked by Dec 15, 2015 at 07:51 PM about the 2000 Chevrolet S-10

Question type: Maintenance & Repair

I have installed the booster and master cylinder from a 2000 S-10 in my 1952 CHEVY. RESTORATION. I did not install the proportioning valve. I have run the lines directly from the master to the front and rear brakes..I am unable to get any brake pedal in spite of repeatedly bleeding the system.
Is the proportioning valve required? Are there other items needed in the system?

9 Answers

12,975

Proportioning valve is to limit the brake pressure in the rear brakes during a panic stop: http://www.freeasestudyguides.com/proportioning-valve-diagnosis.html

1 people found this helpful.
83,865

In other word yes, it would be a good idea to have it, or your rear breaks will be locking up all the time. Brake pedal low? 2 things to check. The rear breaks need to be adjusted up to the drums so as they drag a bit, so the wheel is not free wheeling when you spin it. Then did you bench bleed the master cylinder before putting it on?

83,865

In other words yes, it would be a good idea to have it, or your rear wheels will be locking up on harder breaking. Break pedal low? 2 things to check, the rear break shoes need to be adjusted up to the drums so as the wheel is not free wheeling when you spin it, they should drag a bit. And then did you bench bleed the master cylinder before putting it on?

1 people found this helpful.
15

OK I understand this. Is the lack of the proportioning valve keeping me from building pressure in the entire system? I have bleed the system and have fluid in all the lines and the wheel cylinders but cannot get any pressure built up. Pumping the pedal does not result in fluid discharge from the bleeders. I am a seasoned amateur mechanic and I am stumped.

83,865

Did you bench bleed the master cylinder before putting it on? Also the rear break shoes need to be adjusted up to the drums so they drag a bit.

1 people found this helpful.
15

Yeah I did bleed the master. The rear shoes do need adjusting. I'll try this and install the proportioning valve. Maybe this will help. Anyway thanks for your interest and help.

79,185

Your '52 had a single reservoir system while the '00 has a dual reservoir (required 1967 and forward). A proportioning valve regulates the front to rear pressures for even braking on a disc brake system. You may do better with a late '60s GM master cylinder if you still have drums all around. The chamber for the front half of the braking system on a disc brake set up is larger than the chamber for the rear half. At least it's supposed to be. On a 4 wheel drum set up both chambers are the same size. HTH. -Jim

1 people found this helpful.
Best Answer Mark helpful
15

Still messing with this problem. I have discs on the front and the original '52 drums on the rear. I am trying to use the master cyl. from a 2000 S-10. I do not have a proportioning valve installed.

1 people found this helpful.
79,185

I believe you'll need a proportioning valve on the system to regulate the pressures front to back. To my knowledge all disc/drum systems have always used them. HTH. -Jim

Your Answer:

S-10

Looking for a Used S-10 in your area?

CarGurus has 9 nationwide S-10 listings starting at $2,450.

Postal Code:

Chevrolet S-10 Experts

  • #1
    Andrew Olsen
    Reputation
    2,810
  • #2
    John Saffrahn
    Reputation
    1,110
  • #3
    Trebor66
    Reputation
    1,090
View All

Related Models For Sale

Used Ford Ranger
7 Great Deals out of 284 listings starting at $3,975
Used Chevrolet Silverado 1500
101 Great Deals out of 11,097 listings starting at $4,900
Used Toyota Tacoma
22 Great Deals out of 1,549 listings starting at $6,791
Used GMC Sonoma
4 listings starting at $4,950
Used Ford F-150
124 Great Deals out of 10,948 listings starting at $369
Used Dodge Dakota
6 Great Deals out of 143 listings starting at $3,495
Used Nissan Frontier
12 Great Deals out of 575 listings starting at $5,995
Used Chevrolet Blazer
14 listings
Used GMC Sierra 1500
86 Great Deals out of 10,982 listings starting at $3,880
Used Dodge Ram 1500
26 Great Deals out of 486 listings starting at $3,800
Used Chevrolet Camaro
8 Great Deals out of 1,023 listings starting at $4,500
Used Ford Mustang
21 Great Deals out of 1,308 listings starting at $2,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.