Super Hard Brake Pedal no Brakes

[Manuelsv]

Hopefully someone has some experience on this.

So I replaced my brake lines with extended braided stainless steel lines as part of my recent lift. Fairly easy... did the brakes bleed RR, LSPV, LR, then LSPV again Just in case, then FR and FL.. Always kept fluid in the reservoir making sure it never ran dry. I used a hand pump self bleeder never exceeding 15LB pressure till I had no air coming out!
So to test drive.. I drive it 4-5 miles to pickup some materials for step #6 to congratulate myself on a job well done.. Brakes worked perfectly and at least felt better with the SS lines came out of the store and the brake pedal is super hard, with no power on the brakes... ! Limped it home, recruited my neighbor to help me bleed the system again this time without the hand pump/bleeder and using the 2 man system.. no air in the lines.. and all is good.. Checked vacuum line to the booster.. all good.. Still Super hard brake pedal and no brakes!
Limped it to brakes+ bout a mile down the road for a "free" diagnostic.. And they tell me it's a vacuum problem from the engine! WTF?? Engine runs fine.. if it had no vacuum.. wouldn't the engine stumble or run like crud? So I high tailed it out of there.. I knew I should never let any of those McBrakes places even look at my cruiser.. now I am back to the hive to look for wisdom!

 

[arndog123]

Sounds like a bad brake booster. Check out the following link,
https://forum.ih8mud.com/80-series-tech/398165-bad-brake-booster.html

 

[Squash]

Maybe a stuck caliper...

 

[wesayso]

Sounds like a bad brake booster. Check out the following link,
https://forum.ih8mud.com/80-series-tech/398165-bad-brake-booster.html

+1, that's it

 

[jabhb]

recently hhad the same thing...
i now have all new calipers and a new lspv and it solved the problem!

 

[Manuelsv]

All where bad?

recently hhad the same thing...
i now have all new calipers and a new lspv and it solved the problem!

Why the calipers? did you replace parts till it was good, or where all 3 bad?
I'd hate to just trow money at it..

UPDATE! Checked vacum, all good, so we are assuming it's the booster..
We are going to replace it, I got a place I can order one, try it, and if it does not work return it.. so nothin lost.. I'll post back it that solves it!

 

[JOHNWOHN]

maybe its a floormat problem...

 

[Manuelsv]

maybe its a floormat problem...

Dang it!I'll check the floormat! :whoops:

 

[wesayso]

Did you resolve this yet?

 

[Manuelsv]

It's in the shop getting a new Brake Booster... They put on a new booster yesterday and called me to tell me that it seemed that it was much better but still weak? I did not try it myself, so I don't know the specifics .. But in any event they are swapping out the new booster for another at no additional charge to see if they got a dud on the 1st replacement.
I'll find out tomorrow if that was the fix And report back!

 

[SHREDwagon]

Hmmmm, you replace your brake lines and all's good. A day later and no brakes?

Possibly your booster.

More probable you didn't tighten up the bleeder valves til they seated properly or they are old and not making a good seal. Air infiltrated slowly.....

I say probable, as the exact same thing happened to me. I'm beginning to suspect ALOT of the brake bleeding difficulties are valve related. Either no thread sealent is used and air infiltrates passed the valve, or they aren't re-checked to make sure they're fully seated. In my case I replaced my valves and problem solved....... Good luck.

 

[Squash]

Caliper is frozen = no pressure on pads...this often happens after brake jobs just because rust builds up around the pistons as your pads wear and once the new pads are installed the pistons are forced into the rust and seize.

Therefore clean the pistons and check that they move freely before putting on the tires.
Another thing is to touch your axle and discs for heat after driving to ensure that nothing is sticking.

 

[Manuelsv]

Timing was coincidence?

Had the truck at the shop for almost 2 weeks.
Luckily my mechanic is awesome, and finally figured it out..
He 1st replaced the booster and had the same problem. Looked at the entire system, checked the calipers, LSPV adjustment etc.. and determined the New booster was bad, replaced it with a 2nd unit from another source, and problem fixed !
In the end I paid $240 for the new booster, and $80 in labour
As far as I can guess, my brake bleeding after replacement of the brake lines was just the last straw that broke the old booster's back Anyhow back on the road and ready to hit the trails! Thank you all for the advice.

 

[jonheld]

Just went through this on my truck last week. Swapped in a used booster I found at a local auto recycler.

No way that was an OEM booster for $240. Perhaps that explains why the first one was bad.
A new one priced out at over $700 with my special "Jon Held is a great guy" discount.

 

[jlg32281]

Most auto parts stores sell a Cardone reman unit. Cardone makes quality parts and it's what I chose to buy when my booster went out.

 

[Manuelsv]

Yep, it's a Cardone reman
at $700+ OEM lasted 14 years,
If I get 5-8 from the reman, I'll be happy, Probably wont own the truck by then

 

[yardbird88]

Definitely the booster, it costed me some $450 from dealer parts + $80 labor from my local mechanic.

 

[Snowmonkey]

does your engine drop 100 rpms when you hit the brake at idle while in park? if it does then you have a vacuum leak in the brake booster. mine was 500 bucks rebuilt with labor.