Brake Booster Vacuum Leak

[TheBlueBeast]

I think I have a vacuum leak in my brake booster. It causes my tranny to not shift properly (no 1st or 4th gears), and it makes the single most annoying sound when I pres on the brake. If I let the truck sit and cool down, I get all the gears back and it runs great. Is this the right diagnosisof the problem? If so, how hard is this to fix? Thanks guys, appreciate your input and want to get back to driving the Tahoe, haven't for over a week and I miss it.

 

[jerryjoe28]

vacuum leaks can cause all kinds of problems.... what makes you think it is a vac leac and why in the booster?

 

[TheBlueBeast]

It makes a real nasty squeaking sound and the pedal gets a bit squishy. Plus, when cold, I have all four gears, but when it gets up to operating temperature I lose 1st and 4th. It throws a 2nd and 3rd gear shift solendoid code, but those are the gears I have. I would think that code would mean I wouldn't have those gears but I do. Also, when the gears go away the engine won't go above 2000 RPM. That's the bulk of the information I have.

 

[OR VietVet]

Care to share what year it is and the engine?

 

[TheBlueBeast]

Sorry, forgot that. It's a 1996 4 door, 4x4, with the 350 and 4L60E. I miss driving it, it's been two weeks, can't find a mechanic to work on it, I'm beginning to wonder if I can do it myself.

 

[TheBlueBeast]

*UPDATE*

Found a couple broken ground straps, the one from the cab to the chassis and the tranny to the chassis. That might be the problem.

But, like I said earlier,when cold it runs well, and it's been horrifically cold so I'm waiting for it to hopefully warm up a bit more to see if thats the issue for sure. The SES light was even off when I started it the the other day. Guess only time will tell.