Vacuum/Brake/Idle Question
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Vacuum/Brake/Idle Question
rdhack
5/9/2008 3:35:41 AM
1991 s-10 Blazer 4.3L
Just noticed that while in Park and engine at idle, when I mash down the brake peddle the engine idle picks up and I hear what sounds like a vacuum leak behind the steering wheel in the dash. I have notice that sometimes my brake peddle is hard also. I do have good brakes.
Vacuum Leak Perhaps? Brake Booster going out?
What do you guys think?
Thanks!
Peru Motors
5/9/2008 4:56:13 AM
think brake booster. jp
c0a8l0v6i8n9
5/9/2008 8:21:01 AM
your booster may be going or it could be a leak check for leaks first then go from there
Mine is doing the EXACT same thing. I narrowed it down to the booster but I'm reinvestigating today.
rdhack
5/12/2008 7:52:42 PM
Yep its the Booster..........I have never replaced one before...Does anyone have any tips of what to look for?
I imagine.First disconnect the Master Cylinder....then probably the nuts inside the firewall and the brake pedal........disconnect vacuum hose and lift out.
Does that sound about right? I'm guessing 2 hours. Any special tools needed???
Thanks
obso
5/13/2008 9:28:25 AM
That's pretty much it. Only thing I would say to do different is the order.
vac line-> master cyl-> pedal connection-> inside 2 bolts. rinse, lather, repeat.
And thats just so you don't have to deal with it flopping around while your trying to undo connections and such. 2 hours sounds about right too.
I'm picking a new one up tomorrow from the pick n pull. $13 half price :]
Not looking forward to the four bolts on the firewall, the top two are a pain it looks like.
Deep sockets and an extension should take care of it nicely.
rdhack
5/13/2008 8:08:05 PM
Let me know how it goes ATP....I will not be able to get to mine until probably the weekend.
ATP
5/14/2008 10:34:12 AM
Well I tried getting my leaking booster off before I went to the yard, I cannot for the life of me figure out how to get the top two firewall nuts off without removing most of the dash area around them. I think I'm going to have the family mechanic assist me because Im probably an idiot and missing some easy technique. UGH.
rdhack: You will probably beat me to the punch so YOU let me know how it goes haha.
Update:
Got the right tools for booster removal...
15mm Deep socket and regular socket (Booster nuts/master cylinder nuts and push rod bolt)
Extension
Socket Wrench
Phillips Screwdriver (for dash crap)
Adjustable crescent wrench (used on push rod)
I was working in the dark with a flashlight and managed to get all bolts but one off haha.
What I did:
- Removed all drivers side kick panels
- moved hood release thing
- removed the lower dash panel
- removed the master cylinder nuts
- removed bottom left nut on booster from the interior
- then the top left nut (moved hood release helped)
- then realized i forgot to unhook the brake pedal from the push rod, so unhooked it and used a wire to pull the pedal out of my way
- then the top right nut
And now I'm stuck on the bottom right. I figured out how to get it off though. I have to drop my steering column to get to it easily. Me being an idiot, I did not disconnect the steering so when I tried to drop the column I was wondering why it wouldnt go down easily so I probably bent the shaft, but I'm doing it the non-idiot way tomorrow in the day light by unhooking the linkage so I can drop the column and get that damn nut off. Also I can't pull the master cylinder off the booster because the steel lines to my ABS are all complicated so that just adds to the annoyance. I don't want to unhook the lines to the master cylinder!
I'll keep y'all posted.
rdhack
5/16/2008 4:38:45 AM
Man, I'm thinkin that my mechanic may do this job. The last time I had my dash apart (for a heater core) I swore I'd never do it again. Just got my tax rebate so I think tha's what I'll do!
ATP
5/16/2008 12:54:02 PM
Welp, I got it off in like 10 minutes today. The bottom right nut on the firewall wasn't as bad as it seemed. Instead of dropping the steering column completely, I just took off te Neutral Safety Switch and the socket fit right where it needed to. Wrestling the damn booster out of the engine bay was the pain in the ass, mainly because I left my master cylinder intact.
Really on a scale of 1-10 for difficulty of removal, I'd give that task a 7 if you don't know what you're doing (like me). I will do a how-to for brake booster installation and removal once I go and pull one off a junk Blazer this weekend. It's a shame there's not one write up online that I could find that gives any tips or useful information besides remove all the nuts and whatnot.
I hope to god I don't end up pulling another bad booster at the yard too :\
