LX450 Spongy Brakes (1 Viewer)

[Trail Mule]

Hello ih8mudders!
I am having spongy brakes on my 97 LX450. I had the brakes bled on the front, but they couldn't do the rears, replaced the brake booster, and the brake pads front and rear are all with good padding left on them. The emergency brake is in good working order. I have read that the LSPV could be the problem but before I delete that, I would like to see who else has had this problem and how you fixed it?

 

[audi2nr]

why couldn't they bleed the rears? if they had the master cylinder/booster off there is definitely going to be air in the lines that needs to be bled out..

 

[Trail Mule]

They said they couldn't undo the bleeder screw without breaking it.

 

[mtkreitz]

I dealt with spongy/weak brakes for years on my 80 and then @LandCruiserPhil told me about the need to properly bleed the ABS unit in addition to the LSPV. I bled my brakes using speed bleeders several times but could not get the brakes to improve. Thinking back, my bet is I still had air in the ABS unit.

How do we activate the abs using techstream to bleed brakes?

For the techstream techies...how is the abs activated? I went to the abs ecu but so many options... Which one is it?

forum.ih8mud.com

 

[audi2nr]

They said they couldn't undo the bleeder screw without breaking it.

well they will need to bleed the brakes, you can get new bleeder screws separately usually, now you need to find out which will be cheaper.. the labor to drill out the old bleeder screws or maybe use an easy out or to just replace the calipers, but either way, due to the parts that got replaced you will need to get the lines bled...

 

[jonheld]

They said they couldn't undo the bleeder screw without breaking it.

If the bleeders are that corroded, then it's a good be that the calipers are as well. This is the result of a neglected brake system.
Brake fluid absorbs moisture over time and that corrodes the internals of the system. The darker the fluid, the more contaminated it is. Brake fluid should be water clear and flushed yearly.

 

[Bambusiero]

I have bleed my LX450 brake system several times, with a home-made pressure bleeder. Certainly it can be done unless something is wrong.
1) LSPV (yes, there is a bleeder up there)
2) Rear passenger side
3) rear Driver side.
4) Front passenger side
5) Front drivers side.
Sounds like your rear calipers might need to be removed so they can be worked on on the bench?

 

[BombCity]

Hello ih8mudders!
I am having spongy brakes on my 97 LX450. I had the brakes bled on the front, but they couldn't do the rears, replaced the brake booster, and the brake pads front and rear are all with good padding left on them. The emergency brake is in good working order. I have read that the LSPV could be the problem but before I delete that, I would like to see who else has had this problem and how you fixed it?

There is some good advice in this thread already, but I will add that if your truck is lifted, you will want to make a simple bracket to bring LSPV back up to level. It does affect how the brakes engage, as it applies force based on what it thinks the attitude of the truck is. And yes, as Babusiero said, you do need to bleed that unit as well. My brother @POTATO LAUNCHER and I went through my brakes about this time last year, and my brakes have been spot-on since. Night-and-day difference.

A power bleeder is the way to go. The $30 Harbor Freight bleeder does the job well, but you definitely want to get the air out of the ABS unit as you work through the bleeding process. This takes time, but yields excellent results.

Find a gravel road, or any surface that will allow the ABS to engage, and engage it 10-15 times. Power-bleed all four corners, and the LSPV. Repeat this process until your pedal firms up. We ran through this cycle 2-3 times. I had great pedal feel and it braked hard. Still does. You can also adjust the throw of the pedal itself if you feel engagement is low in the stroke. Mine engages fairly high in the stroke and that feels absolutely correct to me.

Getting the air out of the ABS unit (surprising how much air gets trapped in there) and leveling the LSPV were the two most important pieces of the puzzle, at least on mine.

 

[Cruzerman]

Or you can put the ABS and LSPV in the trash.

 

[BombCity]

Or you can put the ABS and LSPV in the trash.

This is true!