Power assisted brakes
 

I have a question.
I recently had my engine replaced and b4 i did my brakes were perfect.
After the engine was replaced I no longer have power assisted brakes
I can pump brakes and get assist but only for that 1 stop. If i apply brakes again.. No assist.
I replaced vacuum pump and checked check valve and switch all working fine.
Why am I not getting power assist when braking unless I pump brakes
Its a 2005 volvo xc90 t6
Please help!!!!

What does it feel like to have no power assist? High pedal or low?

Low peddle
Unless u pump them then its nice high peddle
Doesnt feel like you have to force the car to a stop with the power assist
Without pumping brakes.. Feels like you have to force the car to a stop everytime.
Any ideas????

Low peddle
Unless u pump them then its nice high pedal
Doesnt feel like you have to force the car to a stop with the power assist
Without pumping brakes.. Feels like you have to force the car to a stop everytime.
Any ideas????

Your problem is air in the lines. No biggie. Just need to be bled. I figured that was what it was.

I thought it was air too..paid for the entire brake system yo be bleed ... They said they bleed it 4x and there is 100% no air left in the system.
Brakes got 10% better. But still no boost.
So whats the next guess??

I would replace the master cylinder. But its hard to diagnose without driving to feel it.

Already checked the master cylinder..its not leaking and all the seals are good.. Booster is also good.
Not sure what else it could be
Thats why I am lost.

How did you check the master cylinder? Also make sure there isn't a big vacuum leak somewhere. Like the plastic pipes going to the turbos. Specifically near the upper engine mount if it has an air baffle on the pipe.

the master cylinder was pressure checked and the seals checked no leaks and holds pressure.
The issue is volvo replaced my engine and b4 they did EVERYTHING worked 100% afterwords no brake boost assist. Yes brakes are new completely bleed and brake check replaced check valves new.. Booster and master cylinder had seals checked and been pressure tested. And vacuum pump replaced. Just trying to see what it is I missed. ?????

It was taken to Meineke and they tested it

Sorry, but not who I would trust. If there isn't a big vacuum leak, I'd put my money on the master. But again, hard to say without driving it and inspecting it myself.

I'm in kansas.. Come see what u think

No thanks