LS swap brake issues (1 Viewer)

[Desslok]

Hi need help. Took possession of an 80 series that was my brothers from a shop in Wisconsin. He had them swap an LS 6.2 L92 with a 6L80 out of an 2007 Escalade into a triple locked 1996. My brother passed away serving in the Middle East last year and I am trying to sell it for my sister in law and her kids. Drove it 1000 from Wisconsin to Colorado Springs, it ran strong but the brakes started to crap out in Omaha. The Toyota booster is working as it should. The brakes are intermittent, working, then very soft, going to the floor to get any engagement, the brake assist doesn't engage. An OEM Toyota valve was placed in the vacuum line from the engine to the master cylinder, still no improvement. Any thoughts? Thanks in advance.

 

[bkfj40]

Does the 80 have abs module or better question - what year 80 you working with?

Where are you located and how much you asking for the truck? Sorry to hear about your brother - good for you for trying to help out his family I’d be willing to lend a hand if you’re in western Virginia

 

[Desslok]

Does the 80 have abs module or better question - what year 80 you working with?

Where are you located and how much you asking for the truck? Sorry to hear about your brother - good for you for trying to help out his family I’d be willing to lend a hand if you’re in western Virginia

Thanks for the reply. It does have an ABS module and is a 1996. I'm in Colorado Springs. The engine has been completely rebuilt by an LS shop in Wisconsin. upgraded cam little over 500hp and TQ at the crank. Drove it 1000 from WI to Colorado Springs ran strong but the brakes started to crap in in Omaha. Not sure what to ask for the truck, too focused on the brakes. I was going to put it on Bring a Trailer, just want to get the best price for my sister in law and her kids. Thanks for the offer with help, you're in Gods Country.

 

[cruisermatt]

Thanks for the reply. It does have an ABS module and is a 1996. I'm in Colorado Springs. The engine has been completely rebuilt by an LS shop in Wisconsin. upgraded cam little over 500hp and TQ at the crank. Drove it 1000 from WI to Colorado Springs ran strong but the brakes started to crap in in Omaha. Not sure what to ask for the truck, too focused on the brakes. I was going to put it on Bring a Trailer, just want to get the best price for my sister in law and her kids. Thanks for the offer with help, you're in Gods Country.

Redline Land Cruisers is right in your back yard if you can't figure it out.

 

[Desslok]

Redline Land Cruisers is right in your back yard if you can't figure it out.

You are right, Redline is great. They have a wait at their shop and my sister in law would like to sell as soon as possible

 

[Kabanstva]

Are you positive there is no air in the brake lines? I had to bleed mine several times before getting them to feel proper. Ended up using a Motive pressurized pump to get the job done. And make sure the LSPV is bled also.

 

[Desslok]

Thanks for the heads up. I hope you are right and it is the LSPV. I've bled the lines twice, going to bleed the LSPV and lines again Monday.

 

[Kabanstva]

Thanks for the heads up. I hope you are right and it is the LSPV. I've bled the lines twice, going to bleed the LSPV and lines again Monday.

The LSPV is probably the most stubborn part as far as bleeding goes.

 

[Broski]

Sorry for you loss !


Most just remove the LSPV when doing a ABS delete.

I would just remove it.

 

[Desslok]

Sorry for you loss !


Most just remove the LSPV when doing a ABS delete.

I would just remove it.

Thanks for the advice. Going to remove the LSPV and do the ABS delete Monday. I'll post how things work out.

 

[White Stripe]

Honestly this doesn't sound like a bad abs or lspv. Sounds like a bad master cylinder to me. If it's original parts, I would replace the lspv, master cylinder, and brake booster. I doubt the abs is a issue. The lspv is easy to replace. I don't know why people delete them. They are kind of a pain to adjust initially I guess.

 

[CrabCake]

This may sound basic, but check your front wheel bearings...if there was work done on the front end when the swap was done, they could be loose. Case in point, I rebuilt my front end with new shafts and did new wheel bearings. Started having intermittent pedal feel where it would drop low on the first pump or two after driving a bit. I couldn't narrow down when and why and it was very frustrating and getting worse. Turns out that when I packed the new bearings, I didn't seat the driver's side well enough and when the grease settled, it was a bit loose...not much, only a 1/4 turn on the nut, but enough so when I would go around turns or bumps, the loose rotor would push the pads back in a bit into the caliper pistons (think when you change pads and need to re-set the pistons with a few light pumps). Drove me nuts until I figured it out. Just a thought for you. You can check by jacking up and put a breaker bar under the tire to try and lift it...if it moves up and down at all, re-set your nut inside of the hub.

I'm a pretty solid shade tree mechanic, and I tried to bleed, pressure bleed, new booster and master, and almost yanked the ABS and LSPV...glad I'm still in stock form...if there's a problem, there's a fix to get you back to factory specs.

Thank you for your brother's service and really sorry for your loss....hoping good karma can bring the family some solid cash with the sale.

 

[Godwin]

The brakes are intermittent, working, then very soft, going to the floor to get any engagement, the brake assist doesn't engage.

Have had these exact symptoms couple of time when the master cylinder was failing.

 

[mudgudgeon]

This may sound basic, but check your front wheel bearings...if there was work done on the front end when the swap was done, they could be loose. Case in point, I rebuilt my front end with new shafts and did new wheel bearings. Started having intermittent pedal feel where it would drop low on the first pump or two after driving a bit. I couldn't narrow down when and why and it was very frustrating and getting worse. Turns out that when I packed the new bearings, I didn't seat the driver's side well enough and when the grease settled, it was a bit loose...not much, only a 1/4 turn on the nut, but enough so when I would go around turns or bumps, the loose rotor would push the pads back in a bit into the caliper pistons (think when you change pads and need to re-set the pistons with a few light pumps). Drove me nuts until I figured it out. Just a thought for you. You can check by jacking up and put a breaker bar under the tire to try and lift it...if it moves up and down at all, re-set your nut inside of the hub.

I'm a pretty solid shade tree mechanic, and I tried to bleed, pressure bleed, new booster and master, and almost yanked the ABS and LSPV...glad I'm still in stock form...if there's a problem, there's a fix to get you back to factory specs.

Thank you for your brother's service and really sorry for your loss....hoping good karma can bring the family some solid cash with the sale.

I've had the same happen on a couple of my cruisers, and other vehicles.
Definitely check front wheel bearings.

Cost zero $$ to check and retorque them.
If you don't know how to set preload on the wheel bearings, let us know or search. It's discussed often. Don't trust the FSM on this.

 

[Desslok]

Sorry for you loss !


Most just remove the LSPV when doing a ABS delete.

I would just remove it.

Thanks for the condolences and reply. Hopefully it is the LSPV. I'm going to be selling it so if I can bleed it and the brakes come back I'll keep it and let the new owner decide.

 

[Desslok]

Honestly this doesn't sound like a bad abs or lspv. Sounds like a bad master cylinder to me. If it's original parts, I would replace the lspv, master cylinder, and brake booster. I doubt the abs is a issue. The lspv is easy to replace. I don't know why people delete them. They are kind of a pain to adjust initially I guess.

Thanks for your reply. tomorrow I'll start by checking the wheel bearings, recheck the master cylinder bleed the system again with special attention on the LSPV.

 

[Desslok]

I've had the same happen on a couple of my cruisers, and other vehicles.
Definitely check front wheel bearings.

Cost zero $$ to check and retorque them.
If you don't know how to set preload on the wheel bearings, let us know or search. It's discussed often. Don't trust the FSM on this.

Thanks for the advice.

This may sound basic, but check your front wheel bearings...if there was work done on the front end when the swap was done, they could be loose. Case in point, I rebuilt my front end with new shafts and did new wheel bearings. Started having intermittent pedal feel where it would drop low on the first pump or two after driving a bit. I couldn't narrow down when and why and it was very frustrating and getting worse. Turns out that when I packed the new bearings, I didn't seat the driver's side well enough and when the grease settled, it was a bit loose...not much, only a 1/4 turn on the nut, but enough so when I would go around turns or bumps, the loose rotor would push the pads back in a bit into the caliper pistons (think when you change pads and need to re-set the pistons with a few light pumps). Drove me nuts until I figured it out. Just a thought for you. You can check by jacking up and put a breaker bar under the tire to try and lift it...if it moves up and down at all, re-set your nut inside of the hub.

I'm a pretty solid shade tree mechanic, and I tried to bleed, pressure bleed, new booster and master, and almost yanked the ABS and LSPV...glad I'm still in stock form...if there's a problem, there's a fix to get you back to factory specs.

Thank you for your brother's service and really sorry for your loss....hoping good karma can bring the family some solid cash with the sale.

Thanks CrabCake, you're not from Maryland are you? All the Marylander's I've worked with love their crab cakes. I hadn't thought of that. The first thing I do tomorrow will check the wheel bearings. Hope you are right, that will make things much easier.

 

[Broski]

Thanks for the condolences and reply. Hopefully it is the LSPV. I'm going to be selling it so if I can bleed it and the brakes come back I'll keep it and let the new owner decide.

I miss read you post, I thought the ABS was already deleted.

I would fore sure leave things how they are and just work on getting them working correctly.

As others have mentioned get the arm on the LSVP reconnect.

Then bleeding the system.

 

[OffRoadScott]

First, I want to pass on my condolences to you and your sister in law.

From what you are talking about in your original post it sounds like the brake booster is going bad. When mine was going bad I had the same symptoms.

If you are in there you might as well replace the booster and master cylinder at the same time.