Brakes bleeding problems

I replaced all of the steel brake lines on my 03 Tundra. Trying to bleed the brakes. Been through about a quart of fluid still have to pump they up 5 or 6 times together decent pedal. I don't see air bubbles coming out when I bleed them. I would think the if the master cylinder was bad I wouldn't have pedal that holds.

Amy thoughts?

 

What order did you bleed the brakes in, and did you bleed the LSPV? The LSPV is located on the frame above the driver's rear tire and rear axle.

 

I bleed PR, DR, PF, DF.

No I did not bleed the LSPV. Bleed screw is stuck on that I doubt I'll get it loose. Shouldn't bleeding the rear cylinders get the air out of the LSPV?

 

The LSPV is going to be a high point in the system, so it will be a place for air to gather. The LSPV has two lines as well, one is the return line to the master cylinder.
If you're pulling from just the wheel cylinders, you're likely getting mostly fluid (and air) from just the feed line on the LSPV, and not the return line.

 

OK, I got the bleeder lose. You were right it was full of air. At this moment I have good pedal.

Thanks for the suggestion

 

Well, I did a final bleed with the engine running. Pedal got worse. I can pump up the brakes with engine off, but with engine started they go to the floor.

Bad master cylinder?

 

The biggest mistake people make with these trucks, other than improperly adjusting the rears - which is often a major source of braking issues and shitty pedal feel - is trying to 'classic' bleed these trucks, i.e. pumping the pedal. They push all the way to the floor and blow out seals, or don't get air out.

Ideal way to bleed these truck is using positive pressure at the MC reservoir. 2nd best way to bleed is hand vacuum at the bleeder.

It is highly likely you still have air somewhere in the system. If so, you're not going to get it out using old school pedal bleeding. If you were able, I'd be shocked.

 

I was pulling a vacuum at the wheels. Ended up doing it the old fashion way with 2 people. I got my best results that way. I'm going to give another try. I did put a board on the pedal to keep from pressing it too far. There's a chance I su ked air in the line. MC got kind of low. Hopefully that's all it is

 

I have faith that's all it is. You'll get it.

 

Did you replace any of the drum brake components? Or just the steel brake lines?

The reason I ask is because the adjustment of the rear brakes on our trucks is absolutely essential to good pedal feel. I was in a similar situation over the summer, I couldn't get a good pedal for the life of me. It ended up being due to a handful of reasons, the most significant being the rear brakes were out of adjustment. You will never, ever get a really good pedal on our trucks without the rear brakes being adjusted.

Also, if you ran the reservoir dry, you'll have to "bench bleed" the master cylinder. This is a fairly simple and straightforward process- look it up on youtube, I'm sure there's plenty of results. This was one of the reasons I couldn't get my pedal to feel firm, I didn't bench bleed the new MC I installed.

 

Yes replaced rear drums, shoes, cylinders. I tried using a vacuum pump to bleed the brakes. It's work all that well. Ended having the Mrs. help. She let the pedal up by accident didn't realize what she did. Once I realized that's what happened they bleed fine. I bleed the LSPV which I didn't do Originally.

 

Make sure you adjust the rears by the book, or the truck will brake like shit. Make sure they're auto-adjusting properly also, there's a thread covering how critical it is, and how to do it. You can eek a lot more out of your braking experience using tips in that specific thread.