Proportioning Valve Resetting and Shuttle Valve Bleed Tool

DISCLAIMER: These videos show my way of doing things. Don't necessarily follow my advice, I could be wrong. You are responsible for your actions. Not me. I will also mention, DO NOT drive your vehicle with this tool installed!

Here is an affiliate link to a tool on Amazon:

[williamallen]

That button looking thing on the left is not a reset button. Which is why you could not press it. It is the stem on the front metering valve. It needs some ware to go when it opens up allowing full line pressure in the front. When the breaks are not applied the valve closes off again, and it retracts back into the body of the combo valve. This is why it has the black rubber cap over it. Just to keep it clean while in operation.

The proper way to reset the switch is to open the opposite side some while someone presses the brake pedal and holds. Then tighten that brake line. If it has been in use for years you may need to apply the brakes in sharp rapid manner. If that doesn't work, it is stuck. Disassembly and replacement of the shuttle's O rings is the solution at that point. As they have hardened, reducing it's ability to move. It can be accessed by unscrewing the rear fixed orifice metering valve on the right side (not the front metering valve on the left)

[superdragon]

Say Bro i just followed your instructions to the and i have owned this truck for 8 years and i have never had brake pressure(stopping power) like i got now...Man you are the Koolest Thanx.

[cameronskaggs]

This was the best video I’ve seen yet I have a 78 Chevy k5. I did a disc conversion on The back. Not too long ago I replaced my master cylinder not even thinking of that conversion your video was self-explanatory. Thank you.

[AL-fygp]

Thanks for the video! I was working on my 1997 dodge ram 2500 4WD. Lost a rear wheel cylinder a few months back. Rebuilt the brakes and bled them. Been trying to figure out why my ABS and BRAKE light were always on but would go off with out 30% pressure on the brake pedal. Chased it thinking it was are in the line for a long time. Reading through the FSM, it mentions the proportioning valve getting tripped with a loss of pressure front or rear but did not explain how to reset it. I tested the switch and verified it was grounded. I also turned on the ignition while the switch was unplugged to verify the lights turned off. They did. When I pulled the rubber cap off the front of the block, the stem was sticking out. I centered it and verified by checking ground. All good now! Thanks!

[pieroramacciato]

First and only vid I've seen on these valves. Well done. Thanks

[msumgej]

Wow. I'm doing a complete brakes system replacement on a 1986 Holiday Rambler motorhome, disc, disc. This info really helps. A later comment says that old hard o rings can be replaced to loosen a stuck valve. Thanks to all contributors.

[jefflynn]

This video saved me so much aggravation and money. It too me 3 minutes to reset mine. Thanks for sharing.

[alchampion]

I converted 3 drum braked Chevrolet trucks to front disc brakes, I never put the proportioning valve in them they worked GREAT. My last was a 71, it always gave me problems until I put a block from an earlier truck.
I’m learning about how they work on my later 80’s & Mid 90’s trucks. Great Video, I’m for sure getting one of these tools. 👍

[alexvelez]

This helps me out so much. I thought I was going crazy today when I tried to bleed the brakes today

[gregchevelle]

My brake kit wasn’t supplies with this and couldn’t figure why I had not front brakes my rear would skid upon stopping quickly.
Thanks for the video, very helpful 🤙

[waterruner]

2 min in is when he actually starts talking about how to fix it

[msumgej]

The flexible rubber brake lines can collapse internally and act like a one way valve. I had one do that, it looked ok from the outside, it would not let the caliper release. An experienced mechanic told me about the problem.

[MuggerMadison]

Thanks, was pulling fluid from my system to remove the old fluid and wala I was not able to draw any more. Quickly deduced that something blocked the flow of the fluid, now I know and have the fix. Thanks for the tool recommendation and how to fix. PS, early model Chevy disk brake conversion...

[maggs]

I bought a booster, master and prop valve combo from summit. Thankfully my brakes bled easily and the instructions never mentioned what that white plastic thing was. Now I know 😉👍

[pompeyroad]

I did the front disk on my 55 Chevy, later my son did the rear "the 4 wheel disk" and could not get the back brakes to work, put a hand adjustable valve in the line going to the back wheel disc... I now see where the problem is, thanks! Finally get my back brakes back on my 55!

[prospexican]

will that cause to get more pressure on one wheel thank other? meaning one of the front ones or one of the rear?

[davebarron]

Slick, my 83 camaro I swapped to disc / disc from disc / drum, and it started out really good, stopped better than ever however, over time I have been loosing my rear brakes I think this may be the answer. At least till I can replace the master, and proportioning valve to a disc / disc unit. My problem is, the later camaro's that had disc / disc, went to metric threads and my 83 is SAE, so I have an extra twist. Thanks so much!

[carlossibonir.]

Please Mr Metrician. My blazer 2000 dont purge. Pedal go to the bottom. We put positive pressure of liquid from the tap of master cilinder. With an air compressor. All 4 purge valves spit liquid well. I believe dont have any air in sistem. With a scanner command a abs purge but sistem dont purge. Can the proportioning valve be the problem?

[Aaraiegathor]

A proportioning valve reduces the pressure in the hydraulic lines to the rear brakes relative to that supplied to the front brakes during heavy braking.

[nFlames]

To stop faster I have used a larger master cylinder like in the older chevy truck 1/2ton to a 3/4 ton master cylinder. If one goes too larger it's harder to stop without brake booster/engine not running one has to use both feet to stop it.