After I finished changing my water pump, my car decided to display its twisted sense of humor. My brakes are now stiff about half the time. It comes and goes. This is annoying and makes the car undriveable.

When the brake pedal is stiff, pressing on it requires too much strength and the car doesn't is impossible to stop. This is very scary and definitely not what I want when driving my car.

I also have absolutely no idea what could be causing this?

I already tried a battery reset to no avail. All I can imagine is that maybe some fuse blew out or somehow my brake master cylinder got damaged, which is highly unlikely given that it is not near the area I was working with. Also, if it were damaged, why would it sometimes work?

Could this be battery related? An electrical fault of some sort?

 

My first choice would be Vacuum leak. Hand over hand the vacuum line running from the master cylinder. Somewhere along the repairs something may have been sat down on the line or leaned on it. The leak will probably be where it enters or exits, but could be a crack along the line. The brakes are vacuum assist thru the brake booster attached to the master cylinder. The Vacuum line fitting can be removed and tested by pushing down on the outer ring and pulling the line out of the fitting. Push down hard on the ring but pull out gently on the line.

 

Alright, I confirmed that it is a vacuum leak. My brake booster/throttle body elbow hose broke... again!

Sigh, I'll have to have it replaced, but finding a replacement is a PITA. Last time, Terry's Jag sent me the wrong hose and they couldn't find the correct one, so I ended up glueing it together. I heard that there is a kit for fixing that hose, so I'll check to see if I can find that.

 

log into Jagbits one of our sponsors. send them an on line parts request and Dan will get back to you. He is always spot with the right part

 

I have decided I'm going to apply the fix from here:

JagRepair.com - Jaguar Repair Information Resource

As seen in this picture:



He removed the throttle body elbow hose, cut up some of it, and used a rubber hose and a couple screw clamps to solve that problem. It worked for him. I think it will work for me. Mine is not broken flush with the thottle body so I could get away with this and it would cost me very little. If that doesn't work, then I'll check with Jagbits.

 

This definitely worked for me. It cured my stiff brakes and slight almost imperceptible roughness to my idle. I'm pleased with the results, and I only spent about $5.