stupid brake question

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Oct 19, 2003 | 01:29 PM

uk1050

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From: indiana

stupid brake question

on the rear brakes does the residual valve go before or after the porportioning valve...........crap or great...thanks either way.
ive seen diagrams one in mid-fifty and one in speedway both done different, and i followed mid-fifty and put it after the apv.

Oct 19, 2003 | 03:32 PM

Earl

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From: Waynesville, OH

Your proportioning valve is there to provide a pressure difference between the front and rear brakes (unless you have a dual-diagonal brake setup). If all four brakes are drum, or all four are disc, you might get by with a single residual valve of the appropriate rating in front of the proportioning valve. I don't like that setup, though, since the proportioning valve may produce different residual pressure to the two braking systems.

The most straightforward way is to put residual valves, with the appropriate ratings for disk (about 2-3 psi) or drum (about 8-10 psi), after the proportioning valve. Put a residual valve on each line coming out of the proportioning valve. If there are two proportioning valve output lines to the front, two front residual valves are needed. If there are two proportioning valve output lines to the rear, two rear residual valves are needed.

Oct 19, 2003 | 03:37 PM

uk1050

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From: indiana

i have disc front and drum rear. i have the correct size for the front and the correct size for the rear. and i know the the porportioning valve goes to the rear brakes i have that first and then the residual valve second is that right

Oct 20, 2003 | 05:03 AM

GreatNorthWoods

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From: Littleton, New Hampshire

On a 29 Ford I built some years ago with a floor mounted master cylinder, I put the 10 psi inline residual valve in the single line going to the rear, right at the master cylinder and the adjustable proportioning valve just in front of where the single line goes into the junction box for each rear wheel. I put the 2 psi residual valve in the single line leaving the master cylinder in the line just before the junction box where it split and went to each front wheel. This seemed to work well.

Oct 20, 2003 | 07:17 AM

Earl

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From: Waynesville, OH

Sounds like a winner to me, Vern.

Oct 20, 2003 | 09:51 AM

koshare

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From: Tucson USA

eci hotrod brakes has a diagram of a typical disc/drum setup (http://www.ecihotrodbrakes.com/image...brakefacts.gif) this diagram is exactly as vern described in his post.

Oct 20, 2003 | 06:02 PM

Earl

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From: Waynesville, OH

The only issue that might differ from the diagram is that some proportioning valves have two rear and two front output lines directly from the valve instead of a single front line and a single rear line that each split. That is the case where you'd need four residual valves as I mentioned in the first post.

One other thing - some proportioning valve blocks have the residual valves built in. You'll want to make sure if that is true before adding other residual valves to the system.