1978 Pontiac Bonneville needs more brake vacuum?

Asked by Jun 05, 2014 at 08:24 PM about the 1978 Pontiac Bonneville

Question type: Maintenance & Repair

Okay. So I'm fixing up this 78
Bonneville and the thing is, it's been
sitting because of a problem no one
wanted to fix about 10 years back.
My uncle switched engines and
dropped a 400 hp 6.6 L engine in it.
The problem is...the brake booster
doesnt have enough vacuum in it to
stop the car...it has about 6 lbs and I
need somewhere above 11 lbs...how
can i increase vacuum? Thanks!

4 Answers

92,555

An engine that size should have excellent vacuum, enough to run your booster, test the vacuum inches at the manifold supply port then compare it to the vacuum at the supply hose at the booster, the readings should be the same, if not, there is a problem with the supply line, if it is the same, but drops when you hook it up to the manifold vacuum then there is a leak in the booster. HTH

Best Answer
92,555

Unless the engine is supercharged then it won't work that way at all. You will have to install an auxiliary vacuum pump on the engine to provide enough stable supply for your brakes.

You know alot about this can you get in touch with me?

92,555

I guess I could, give me your number or e-mail and I'll try to get back to you in the afternoon pacific time, got a lot going on Friday..

Your Answer

Add photo

Related Questions

Bonneville

Looking for a Used Bonneville in your area?

CarGurus has 536 nationwide Bonneville listings starting at $1,799.

ZIP:

Search Pontiac Bonneville Questions

Pontiac Bonneville Experts

#1 ticklemedaly
ticklemedaly
Reputation 380
#2 dandyoun
dandyoun
Reputation 360
#3 Js08016
Js08016
Reputation 350
View All

Related Models For Sale

Used Pontiac Grand Prix
29 Great Deals out of 2,867 listings starting at $1,500
Used Chevrolet Impala
585 Great Deals out of 31,590 listings starting at $799
Used Buick Regal
110 Great Deals out of 10,820 listings starting at $3,995
Used Dodge Charger
405 Great Deals out of 28,088 listings starting at $1,988
Used Chevrolet Camaro
214 Great Deals out of 30,767 listings starting at $1,217
Used Chevrolet Monte Carlo
20 Great Deals out of 1,396 listings starting at $1,995
Used Chevrolet Malibu
917 Great Deals out of 79,610 listings starting at $1,500
Used Pontiac Grand Am
1,223 listings starting at $1,999
Used Pontiac Firebird
10 Great Deals out of 733 listings starting at $3,875
Used Buick LeSabre
14 Great Deals out of 1,931 listings starting at $995
Used Ford Mustang
460 Great Deals out of 45,656 listings starting at $1,999

Used Cars For Sale

2005 Pontiac Bonneville For Sale
69 listings starting at $2,995
2004 Pontiac Bonneville For Sale
74 listings starting at $1,799
2003 Pontiac Bonneville For Sale
85 listings starting at $3,400

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.