Hitting the brakes and the engine revs.

BeepBeepRR

Well-Known Member
Local time
10:23 PM
Joined
Oct 16, 2016
Messages
9,065
Reaction score
13,933
Location
Atlanta,Ga
OK this problem has just surfaced on the car my old 440 is in. A while back I installed one of those goofy offset CPP brake boosters on the car. The same one is on the Road Runner and both have crappy brakes but both were fine to start with. I think I know the answer to the question.

I think the crappy brake boosters are failing internally. And a vacuum leak causes the engine to rev when you hit the brakes. This is not the issue with the roadrunner. I think that's just a lack of vacuum since I installed the new cam in that. I won't have the car here until tomorrow to find out what's up with it. Just figured I would post and get opinions. Thanks

The car is a 1971 Plymouth Satellite. Any booster suggestions would be appreciated. I don't like the offset ones at all.

The offending booster is one of these types.
?u=https%3A%2F%2Fimg.auctiva.com%2Fimgdata%2F5%2F5%2F2%2F9%2F3%2F1%2Fwebimg%2F937625122_tp.jpg
 

Lefty71

FBBO Gold Member
FBBO Gold Member
Local time
10:23 PM
Joined
Mar 8, 2018
Messages
2,828
Reaction score
3,059
Location
Ohio
Never had that problem with a Mopar specifically....... But I think that angle fitting that you can barely see in your pic is supposed to be an integrated check valve. If it sticks or fails, it can make the motor rev, and in some cases nearly stall.
***edit*** maybe check valve is the wrong term....maybe more like a restriction or orifice that could come loose or fall into the booster. Either way, every time you hit the brakes, it shoves a ton of air into the intake manifold, temporarily dropping your motor vacuum.
 

BeepBeepRR

Well-Known Member
Local time
10:23 PM
Joined
Oct 16, 2016
Messages
9,065
Reaction score
13,933
Location
Atlanta,Ga
I will find out more when it gets here. But you may be correct.
 

BeepBeepRR

Well-Known Member
Local time
10:23 PM
Joined
Oct 16, 2016
Messages
9,065
Reaction score
13,933
Location
Atlanta,Ga
Maybe your throttle cable is too short? LOL!
Not my car but I did install the Lokar setup. This car owner could mess up a wet dream. So I guess we will see what it is when he gets it here.
 

RemCharger

Well-Known Member
Local time
9:23 PM
Joined
Apr 5, 2014
Messages
3,497
Reaction score
3,152
Location
Sask
In a nutshell; those things are junk.
Never seen one work well.
 

BeepBeepRR

Well-Known Member
Local time
10:23 PM
Joined
Oct 16, 2016
Messages
9,065
Reaction score
13,933
Location
Atlanta,Ga
In a nutshell; those things are junk.
Never seen one work well.
I didn't like them when I installed them. I would have never put one on my car. 2 of them installed 2 of them took a crap in a year or so.
 

hemi446

Well-Known Member
Local time
10:23 PM
Joined
Mar 14, 2014
Messages
91
Reaction score
72
Location
Ellicott City Md
Another problem could be it looks like it is from a 1980s Chevy Van. We all know nothing on a Chevy works right after just a couple of years. Just putting it out there I could be wrong.
 

BeepBeepRR

Well-Known Member
Local time
10:23 PM
Joined
Oct 16, 2016
Messages
9,065
Reaction score
13,933
Location
Atlanta,Ga
Got the car here yesterday. Pulled the vacuum line off and capped it. Hit the brakes and no idle up of the engine. Put the hose back on the booster and hit the brakes the engine revs up. So its an internal leak on the booster. Contacting Summit for a replacement. Great now I get to replace junk with junk.
 

BeepBeepRR

Well-Known Member
Local time
10:23 PM
Joined
Oct 16, 2016
Messages
9,065
Reaction score
13,933
Location
Atlanta,Ga
Summit is sending me another booster, should have it tomorrow. So we shall see if this is indeed the issue.
 

BeepBeepRR

Well-Known Member
Local time
10:23 PM
Joined
Oct 16, 2016
Messages
9,065
Reaction score
13,933
Location
Atlanta,Ga
The new booster came today and 30 minutes later we have brakes again. Just a pain in the *** to return this crap. But with Summit 60 miles away shipping is next day fast.
 
Top