LPSV Bypass Problems (1 Viewer)

[Red Merle]

I thought the hissing was a sign that the booster was going?

As for the caliper, I had great luck with the Napa Eclipse Series. They are OEM cores that have been remanned and painted for longer life.

 

[Darne]

Rinse your power bleeder with denatured alcohol, including the hoses, and it will last longer.

 

[1973Guppie]

I thought the hissing was a sign that the booster was going?

As for the caliper, I had great luck with the Napa Eclipse Series. They are OEM cores that have been remanned and painted for longer life.

might still be, luck is not on my side, that and old age of these parts. Gonna replace this caliper first and try to get the truck bled. The hising I could not tell if it was just the normal sound of the brake pedal with the engine off or a problem.

 

[1973Guppie]

SUCCESS!!

Finished up replacing the bad rebuilt caliper. It was indeed a bad unit straight out of the box. I guess that's what you have to put up with when you don't want to pay $300 for new calipers. Bolted on the new caliper, used the power bleeder to bleed out all 4 corners. I got lots more air out this time. I learned that I needed to give another half turn on the bleeders to ensure they are completely open and watch the fluid flow from them for awhile to ensure it was clear with no bubbles. I think the power bleeder really helped push alot more air through the lines and it made the whole process much easier. I just don't think the pump pedal method was giving enough pressure to move enough fluid through the system. I had great results from setting the power bleeder at 20psi and bleeding all 4 corners.

The results were a much higher pedal. The overall top of the pedal is still somewhat soft at the top but I believe that is what it should be like with this truck and the abs unit. I did notice that the overall pedal pressure needed to activate the brakes has gone down alot. This is probably because the rear brakes are actually doing something now vs. before they were literally doing nothing as the lpsv was not allowing them to. I also noticed that the end result of the braking is much smoother will less body roll forward. Since the rear brakes are working now the truck just feels overall more stable during braking down hills, etc. I did not install a manual valve and have no plans to. I don't see it as being an issue as the front brakes clamp much more than the rear and I am usually carrying alot of weight in the rear even when not loaded up for a trip.

In summary I would highly recommend removing the stock lpsv if yours is not working properly and you notice that yoru rear brakes are doing nothing.

 

[FJP971]

Which power bleeder did you buy? Glad you got it sorted out. Just a note; usually when there is air in the lines you can pump the brakes a few times and the pedal gets firmer every time because the air gets compressed.

 

[1973Guppie]

Which power bleeder did you buy? Glad you got it sorted out. Just a note; usually when there is air in the lines you can pump the brakes a few times and the pedal gets firmer every time because the air gets compressed.

motive power bleeder

 

[1973Guppie]

Which power bleeder did you buy? Glad you got it sorted out. Just a note; usually when there is air in the lines you can pump the brakes a few times and the pedal gets firmer every time because the air gets compressed.

yeah I figured it was always air in the lines, after the first bleed I took the truck out and got the abs to actuate 4x and I think that really moved the air out of the abs unit, I think when I unhooked the line from the abs unit I got some air in there that was not coming out during the first bleed, not sure if it was the actuation of the abs or the power bleeder that made the difference but the combo worked nicely. I am tempted to take it out and actuate the abs again and rebleed to see if I can make it even better but in my experience and from others comments the brakes are only so good on these heavy old pigs.

 

[scrowley]

If you want amazing brakes just delete the abs. Expecially with larger tires.

I literally replaced everything in my brake system years ago. I mean everything. Was at multiple shops running gallons of fluid through the system with power breeders. This was after I exhausted all posibbilties and second guessing myself. It happens.

Long story short. I read @jcardona post one day on bad abs units.... i went in shop and deleted abs unit for $0 !!

Pulled out of shop with most anazing brakes ever. I just bought another 80 recently and I ripped the unit out right away. Mint brakes on that one now also.

 

[Red Merle]

If you want amazing brakes just delete the abs. Expecially with larger tires.

I literally replaced everything in my brake system years ago. I mean everything. Was at multiple shops running gallons of fluid through the system with power breeders. This was after I exhausted all posibbilties and second guessing myself. It happens.

Long story short. I read @jcardona post one day on bad abs units.... i went in shop and deleted abs unit for $0 !!

Pulled out of shop with most anazing brakes ever. I just bought another 80 recently and I ripped the unit out right away. Mint brakes on that one now also.

I second that. I see people saying that the brakes on these trucks are always going to be marginal and that just isn't true. My brakes are also amazing. I have never had such a large vehicle that has had better feeling and stopping power.

It would only take a few bucks worth of connections to just try it without the ABS if someone is nervous about going all the way. I would at least want to try it out if I was still dealing with the marginal sketchbox I was handed by the PO.

 

[1973Guppie]

I second that. I see people saying that the brakes on these trucks are always going to be marginal and that just isn't true. My brakes are also amazing. I have never had such a large vehicle that has had better feeling and stopping power.

It would only take a few bucks worth of connections to just try it without the ABS if someone is nervous about going all the way. I would at least want to try it out if I was still dealing with the marginal sketchbox I was handed by the PO.

I get what you guys are saying and believe me it is still on the long list of "to do's". Deleting the abs will probably be something I do in the future just to get better overall brakes but for now it has to wait. Busy life, 2 kids, job and an fj40 I have to get done and sold. Most likely the abs delete will get done when I tear the whole truck down to paint it with monstaliner, but that won't happen probably for a few years.

 

[1973Guppie]

took the truck on a trip to joshua tree with my daughter for the weekend, no real 4x4ing but was very happy with how the brakes performed. A world of difference in stopping power. I get so much more stopping power even from minimal braking pressure now, probably because the rear brakes are now doing their part as before they were doing nothing. No more nose dive under hard braking and the most noticeable was the braking when coming down mountain passes. Having all 4 wheels braking makes a world of difference and really helps with control in curves etc. I wish I had removed the lspv years ago.

 

[1973Guppie]

I would add that I really see no need to remove the abs any longer unless the abs unit starts to give me problems.