Drums don't stop at all after rebuid.

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Mar 20, 2021
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Allen Texas
Had to rebuild my 91 rear drums. New rotors, pads, and hardware. I also upgraded to 95 rotors/calipers, new booster and master cylinder. When the vehicle is jacked up and put it in drive I hit the brakes and the rears only slowly come to a stop, fronts stop immediately. the emergency brake keeps them solid so it must be a pressure issue? I have read about the LSPV so I removed it and tied it up as high as it would go, no difference. Thinking it is bad and should bypass it. I would still want a proportional valve there but what should I buy? Does anyone have a link?
 
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Sep 25, 2014
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We assume you bled the system correctly including the LSPV?

There are a few write ups on how to delete the ABS and LSPV, I did that on mine and the difference is night and day.

ABS/LSPV delete

The link above is the one I used for my truck.

You can also plumb in a portioning valve as well.

JCardona ABS/LSPV delete with valve

The Wilwood valve uses a M10 bubble flare while our lines M10 inverted flare so you will have to either make new lines so you have the proper fitting for the Wilwood valve.

You can also buy adapters from this seller on Ebay.

M10 Inverted to M10 Bubble flare

This information was provided to me from @jcardona1
 
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Did you ADJUST the shoes out like you're supposed to?

They have self adjusters, but you have to back up and go forward like 50 times before they are adjusted properly.
 
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Did you ADJUST the shoes out like you're supposed to?

They have self adjusters, but you have to back up and go forward like 50 times before they are adjusted properly.
The rear shoes are auto-adjusted by use of the hand brake. Has nothing to do with direction of travel.
That said, a manual adjustment is required after shoe replacement to get them to a reasonable starting point. This is all spelled out in agonizing detail in the FSM.
I would suspect that either there is air in the lines or parts installed incorrectly. Drum brakes are very simple in operation, but have lots of internal parts.
It could also be as simple as handling the drum with greasy hands and getting some grease on the shoes or drum surface.
 
Joined
Mar 20, 2021
Messages
179
Location
Allen Texas
We assume you bled the system correctly including the LSPV?

There are a few write ups on how to delete the ABS and LSPV, I did that on mine and the difference is night and day.

ABS/LSPV delete

The link above is the one I used for my truck.

You can also plumb in a portioning valve as well.

JCardona ABS/LSPV delete with valve

The Wilwood valve uses a M10 bubble flare while our lines M10 inverted flare so you will have to either make new lines so you have the proper fitting for the Wilwood valve.

You can also buy adapters from this seller on Ebay.

M10 Inverted to M10 Bubble flare

This information was provided to me from @jcardona1
I did bleed the system and found no bubbles, however, I didn't specifically bleed the LSPV, is that a separate process? Thanks for the links.
 
Joined
Mar 20, 2021
Messages
179
Location
Allen Texas
The rear shoes are auto-adjusted by use of the hand brake. Has nothing to do with direction of travel.
That said, a manual adjustment is required after shoe replacement to get them to a reasonable starting point. This is all spelled out in agonizing detail in the FSM.
I would suspect that either there is air in the lines or parts installed incorrectly. Drum brakes are very simple in operation, but have lots of internal parts.
It could also be as simple as handling the drum with greasy hands and getting some grease on the shoes or drum surface.
Hand brake clicks like 7 times and engages holding the wheels very tight. I adjusted the brakes until they started to drag, then backed off a bit.
 
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Vallejo, CA
You have to bleed while on ground because the proportional valve thinks there is no load at rear and cuts flow to rear calipers/cylinders.

Many forget to extend/adjust the brake proportioning valve when lifting height, reason for rear brakes barely working. You can get at Dobinsons or make yourself.
 
Joined
Mar 20, 2021
Messages
179
Location
Allen Texas
We assume you bled the system correctly including the LSPV?

There are a few write ups on how to delete the ABS and LSPV, I did that on mine and the difference is night and day.

ABS/LSPV delete

The link above is the one I used for my truck.

You can also plumb in a portioning valve as well.

JCardona ABS/LSPV delete with valve

The Wilwood valve uses a M10 bubble flare while our lines M10 inverted flare so you will have to either make new lines so you have the proper fitting for the Wilwood valve.

You can also buy adapters from this seller on Ebay.

M10 Inverted to M10 Bubble flare

This information was provided to me from @jcardona1
Since that Wilwood proportioning valve has one inlet and one outlet, I assume I need an M-10 1.0 elbow connector to eliminate the by-pass line up front? Do you happen to have a link to one of those?
 
Joined
Mar 20, 2021
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Allen Texas
You have to bleed while on ground because the proportional valve thinks there is no load at rear and cuts flow to rear calipers/cylinders.

Many forget to extend/adjust the brake proportioning valve when lifting height, reason for rear brakes barely working. You can get at Dobinsons or make yourself.
I have all four wheels jacked on the axle so I assume that would be the same as being on the ground, all the weight is on the axles. I did remove the LSPV arm and tied it in the full load position and it didn't seem to make much of a difference. I'm going to try to bleed the LSVP and if that doesn't work, I'm going with @OffRoadScott deletion solution.
 
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Just skimmed and didn't read jacked on axles. If vehicle is lifted, just undo lever on axle and push up to allow bleeding.

I spent a week figuring this out on mine. And before that I was always wondering why rear brakes did not work when coming off a boulder or when high speed braking on dirt, it would always swing the rear out.
 
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Allen Texas
Just skimmed and didn't read jacked on axles. If vehicle is lifted, just undo lever on axle and push up to allow bleeding.

I spent a week figuring this out on mine. And before that I was always wondering why rear brakes did not work when coming off a boulder or when high speed braking on dirt, it would always swing the rear out.
I I bled the brakes with the LSPV arm in the stock location, my truck is lifted 2.5" so maybe I should take it off, tie it up high and re-bleed the brakes? Thanks for your input.
 
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Hand brake clicks like 7 times and engages holding the wheels very tight. I adjusted the brakes until they started to drag, then backed off a bit.
I have found that the first adjustment after changing shoes is often too loose. The shoes need to move themselves into the correct position. I do this by using a large flatblade and working the bellcranks half a dozen times while rotating the wheel by hand.
You're going for a max of 7 clicks on the handbrake as a starting point.
 
Joined
Apr 14, 2016
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Oregon
LSPV arm in the stock location, my truck is lifted 2.5"

Unrelated to bleeding brakes, you should lower the LSPV body.


If your LSPV is working and you're even remotely close to the correct mounting height, the rear brakes should bleed just fine.
 
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Unrelated to bleeding brakes, you should lower the LSPV body.


If your LSPV is working and you're even remotely close to the correct mounting height, the rear brakes should bleed just fine.

Never heard of that before. I will lower it by .25" to see if that has an effect. Thanks for the insight.
 
Joined
Mar 20, 2021
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Allen Texas
I have found that the first adjustment after changing shoes is often too loose. The shoes need to move themselves into the correct position. I do this by using a large flatblade and working the bellcranks half a dozen times while rotating the wheel by hand.
You're going for a max of 7 clicks on the handbrake as a starting point.
Yeah, that's what I did. Once I could hear the pads rubbing and it became harder to turn the wheel, I backed off a turn. I might be able to tighten them up a hair more.
 
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Never heard of that before. I will lower it by .25" to see if that has an effect. Thanks for the insight.

If your lift netted 2.5 actual inches of lift, then you should move it something like .16".

Take the measurements from the flare to the center of the wheel, compare to the agreed upon stock value, and do the math that's laid out in that thread.
 

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