Do I really need the Brake load Proportioning valve? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Scrub · 06-30-2003, 12:34 AM

I have an 86 K-30 truck with duals.
It has the funky valve that sits near the rear end and changes (supposedly changes) the brake proportioning when a heavy load compresses the springs.

The sack of worms is leaking fluid pretty bad. I really don't want to replace it. Can I just remove the darn thing.

The linkage on mine is bent anyway and it can't be working correctly, besides which, I have such a huge spring pack, it would take like 3 tons to make the springs move. There must be 12 springs in the main pack and 8 in the overloads. Yes it rides like a tank....No, probably worse.

Thanks in advance

PHOENIX · 06-30-2003, 11:51 AM

I wouldnt remove any brake components if I were you.
Are ou talking about the valve that allows the front and rear brakes to work on different pressure?

I say replace it or upgrade it, but do not remove it.
We would hate to see you wreck a truck full of logs in the back

Scrub · 06-30-2003, 12:26 PM

Thanks Phoenix,
The truck is from the Phoenix School District :-)

Actually it is a valve at the rear axle that limits the amount of pressure applied to the rear brakes when there is no load. My other truck has the same brakes, but it is an earlier truck and dosen't have the valve.
I really don't think the valve is necessary, and in fact I think it is more of a hazzard than removing it would be. I just wanted to see if anyone knew much about it.
Most people disable it when they put lift kits on as the linkage no longer fits.

My fear is that it is always limiting my rear brakes even when I have a big load.

FYI- it has Hydro boost master cylinder.

Thanks

44th Miss Inf · 06-30-2003, 12:43 PM

Scrub,
I removed one from my 84 3/4T 4x4 and have had no problems. The levers were bent, and when I added the extra spring pack, it wouln't have worked anyways.
Like I said, I have had no problems

Virgil

PHOENIX · 06-30-2003, 01:01 PM

didnt know about such an animal.

44th Miss Inf · 06-30-2003, 01:20 PM

Phoenix,
It is a basically control valve that works off ride height. Never seen one work right.
Way I look at it is, if I'm pulling something heavy enough to change ride height, I'll use my trailer that has brakes.

I think it was just another of GMs "80s ideas" as I call 'em.
Virgil

Scrub · 06-30-2003, 02:18 PM

Thanks Virgil,

That's what I wanted to hear

*1FaastC10* · 06-30-2003, 06:09 PM

anybody have pics of the setup?

Scrub · 06-30-2003, 08:03 PM

Here is mine, leaking and with miss-aligned linkage.

apstguy · 07-01-2003, 04:14 PM

Hmmmm. It would be cool if i actually worked! I've had my bed loaded to the max with dirt & sod and could have used that.

Grim Reaper · 07-02-2003, 12:05 PM

Mine in my 88 3/4 burb works. I had my dobts so I messed with it. That 14ff has enough brakes that I can't power brake the truck. Disconnected the linkage and turned it like the rear came up 3 inches and Smke the tires no problem. Did the revers and just about couldn't stop without locking.

If it's leaking then trash it. if you have a problem with lock up then get a willwood adjustable for $50. Mounted in the wheel weel and adjust when you get it loaded.

Scrub · 07-02-2003, 01:02 PM

Quote:

adjust when you get it loaded

Most of the stuff I mess with when I'm loaded get so fouled up that I have to redo it when I get sober!!

Dooh...

Well, I just got done removing it. It was really simple. The valve had a larger flare going out to the axle, but the piece that I needed to plumb together matched fine.

I will report the results back after I drive it. I really don't do a lot of power braking with the old dual wheel farm truck, but then again my wife does drive it once in a while :-)

Thanks.

06-30-2003, 12:34 AM	#1
Scrub Collector of rusty Items Join Date: Dec 2001 Location: Sisters,Oregon USA Posts: 731	Do I really need the Brake load Proportioning valve? I have an 86 K-30 truck with duals. It has the funky valve that sits near the rear end and changes (supposedly changes) the brake proportioning when a heavy load compresses the springs. The sack of worms is leaking fluid pretty bad. I really don't want to replace it. Can I just remove the darn thing. The linkage on mine is bent anyway and it can't be working correctly, besides which, I have such a huge spring pack, it would take like 3 tons to make the springs move. There must be 12 springs in the main pack and 8 in the overloads. Yes it rides like a tank....No, probably worse. Thanks in advance __________________ Scrub Sisters, Oregon - Home of the Sisters Rodeo. 70 GMC 1,000,000 + miles 72 K-20 project, 456 Dana60 front, Corp14 rear w/locker, 265R19.5 tires 20-ply. Warn 12k winches both ends, Cross-over steering with raised tie-rod, Powerbox steering, 4500 watt 120-AC power, Air, Hydraulic aux power, 4 inch lift, 5000 lb air-bags both ends.

06-30-2003, 11:51 AM	#2
PHOENIX Registered User Join Date: Oct 2002 Location: Phoenix, Arizona Posts: 4,703	I wouldnt remove any brake components if I were you. Are ou talking about the valve that allows the front and rear brakes to work on different pressure? I say replace it or upgrade it, but do not remove it. We would hate to see you wreck a truck full of logs in the back __________________ * AVOID: LOPER'S PERMORANCE / LOPERSPEED.COM OF PHOENIX, AZ & COTTMAN TRANSMISSION *

06-30-2003, 12:26 PM	#3
Scrub Collector of rusty Items Join Date: Dec 2001 Location: Sisters,Oregon USA Posts: 731	Thanks Phoenix, The truck is from the Phoenix School District :-) Actually it is a valve at the rear axle that limits the amount of pressure applied to the rear brakes when there is no load. My other truck has the same brakes, but it is an earlier truck and dosen't have the valve. I really don't think the valve is necessary, and in fact I think it is more of a hazzard than removing it would be. I just wanted to see if anyone knew much about it. Most people disable it when they put lift kits on as the linkage no longer fits. My fear is that it is always limiting my rear brakes even when I have a big load. FYI- it has Hydro boost master cylinder. Thanks __________________ Scrub Sisters, Oregon - Home of the Sisters Rodeo. 70 GMC 1,000,000 + miles 72 K-20 project, 456 Dana60 front, Corp14 rear w/locker, 265R19.5 tires 20-ply. Warn 12k winches both ends, Cross-over steering with raised tie-rod, Powerbox steering, 4500 watt 120-AC power, Air, Hydraulic aux power, 4 inch lift, 5000 lb air-bags both ends.

06-30-2003, 12:43 PM	#4
44th Miss Inf Registered User Join Date: Sep 2002 Location: Liberty, Mississippi Posts: 672	Scrub, I removed one from my 84 3/4T 4x4 and have had no problems. The levers were bent, and when I added the extra spring pack, it wouln't have worked anyways. Like I said, I have had no problems Virgil Last edited by 44th Miss Inf; 06-30-2003 at 01:14 PM.

06-30-2003, 01:01 PM	#5
PHOENIX Registered User Join Date: Oct 2002 Location: Phoenix, Arizona Posts: 4,703	didnt know about such an animal. __________________ * AVOID: LOPER'S PERMORANCE / LOPERSPEED.COM OF PHOENIX, AZ & COTTMAN TRANSMISSION *

06-30-2003, 01:20 PM	#6
44th Miss Inf Registered User Join Date: Sep 2002 Location: Liberty, Mississippi Posts: 672	Phoenix, It is a basically control valve that works off ride height. Never seen one work right. Way I look at it is, if I'm pulling something heavy enough to change ride height, I'll use my trailer that has brakes. I think it was just another of GMs "80s ideas" as I call 'em. Virgil

06-30-2003, 02:18 PM	#7
Scrub Collector of rusty Items Join Date: Dec 2001 Location: Sisters,Oregon USA Posts: 731	Thanks Virgil, That's what I wanted to hear __________________ Scrub Sisters, Oregon - Home of the Sisters Rodeo. 70 GMC 1,000,000 + miles 72 K-20 project, 456 Dana60 front, Corp14 rear w/locker, 265R19.5 tires 20-ply. Warn 12k winches both ends, Cross-over steering with raised tie-rod, Powerbox steering, 4500 watt 120-AC power, Air, Hydraulic aux power, 4 inch lift, 5000 lb air-bags both ends.

06-30-2003, 06:09 PM	#8
1FaastC10 Account Suspended Join Date: Oct 2002 Location: Elkhart, IN Posts: 6,399	anybody have pics of the setup?

06-30-2003, 08:03 PM	#9
Scrub Collector of rusty Items Join Date: Dec 2001 Location: Sisters,Oregon USA Posts: 731	Here is mine, leaking and with miss-aligned linkage. Attached Images __________________ Scrub Sisters, Oregon - Home of the Sisters Rodeo. 70 GMC 1,000,000 + miles 72 K-20 project, 456 Dana60 front, Corp14 rear w/locker, 265R19.5 tires 20-ply. Warn 12k winches both ends, Cross-over steering with raised tie-rod, Powerbox steering, 4500 watt 120-AC power, Air, Hydraulic aux power, 4 inch lift, 5000 lb air-bags both ends.

07-01-2003, 04:14 PM	#10
apstguy LED King Join Date: Jan 2003 Location: Sacramento, CA Posts: 2,087	Hmmmm. It would be cool if i actually worked! I've had my bed loaded to the max with dirt & sod and could have used that. __________________ Tyler 1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles 2006 Ford Focus ZX3 5-speed Stick 2016 Chevy Spark EV Gone: 2002.5 VW GTI 24v VR6 Gone: 2008 VW R32

07-02-2003, 12:05 PM	#11
Grim Reaper Registered User Join Date: Jul 2001 Location: Atlanta GA Posts: 1,704	Mine in my 88 3/4 burb works. I had my dobts so I messed with it. That 14ff has enough brakes that I can't power brake the truck. Disconnected the linkage and turned it like the rear came up 3 inches and Smke the tires no problem. Did the revers and just about couldn't stop without locking. If it's leaking then trash it. if you have a problem with lock up then get a willwood adjustable for $50. Mounted in the wheel weel and adjust when you get it loaded. __________________ Grim-Reaper 70 Pontiac LeMans Sport Convertible, worlds longest resto in progress Looking for 71-72 2wd Blazer or Jimmy Project

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