Hey everyone, I've read about this issue before here, but I'd like to gather the latest and greatest solutions and possible causes in this post.

Some months ago my gf's X-type started to lose brake assist (hard pedal) which eventually caused her to rear end another car. While I'm fixing everything that broke in the crash, I need to figure out how to fix the brake issue to make the car safe again.

A couple of months before power braking failed, I've replaced the front pads and disks as they were very unevenly worn out (lack of maintenance). After that I asked a shop to do a brake fuild flush.

What I know so far:

1. manifold vacuum is ok, measured with a vacuum meter
2. manifold to booster (servo) pipe seems ok, the one way valve works for sure, despite looking a bit worn out on the outside (engine heat)
3. when the car is started with the pedal depressed, it doesn't go down enough I think (as per the workshop manual test)

What I'm not sure about:

1. if there was a leak at the joint of the bootster pipe and the manifold, would the engine be running rough?
2. how do I tell if the booster itself is ok?

I've looked at the bolt locations for the booster and it looks like a pain to swap out, so I probably won't be doing it myself, but before I do buy a new one and pay the shop fees, I'd like to rule out some other faulty bits that might be cheaper to fix. Any advice on tackling this?

 

https://www.jaguarforums.com/forum/x...-brakes-57314/

 

brake booster, or servo, is common to go bad. i just replaced mine with the same issue. as for a leak around the lines. while running spray starting fluid around the connections if the engine revs up, there is a leak