Vintage Mustang Forums banner

1 - 6 of 6 Posts
G

·
Guest
Joined
·
0 Posts
Discussion Starter #1
I am looking to increase the vacuum pressure going to the power brake booster on my 66 drum/drum setup. The brakes are very hard to press. I have a 289 'c' engine. Right now the vacuum line tees of a smaller line going to the transmission. When I take off the air cleaner, I see lots of bolts that look for mounting purposes. I only see the one hole used for vacuum. Are there others that I can not see? What is my best way to increase the vacuum pressure?

Thanks... Dave
 

·
Registered
Joined
·
3,486 Posts
As far as I know, all vacuum comming from the intake is the same, no matter where the fitting is. You appear to be connected to the right source.

[color:blue]68 GT500</font color=blue>
[color:green]68 1/2 CJ Coupe</font color=green>

MCA# 18519
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #3
Manifold vacuum should be pretty much the same no matter what port it's taken off of. Your stiff brakes might be due to something like a vacuum leak in the booster.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #4
I don't think that there is any way to increase vacuum to the brake servo. If you experience stiff brakes that may be caused by a vacuum leak, but that would also cause uneven running of the engine as the fuel-air mixture is no longer correct.

Stiff braking may also be due to pistons that don't move up and down their bores smoothly. This may have been caused by oxidation.

When was the last time you replaced the brake-fluid?
The reason I mention this is because I did this recently and found some sludge-like deposits in the reservoir. I can imagine them restricting fluid flow once they enter the brake lines.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #5
This booster was installed about six months ago. I rebuilt the m.c. at that time. My mechanic installed the booster and put all new fluid in then. I asked him about the stiffness, and he said that is normal. I don't believe it, that is why I am asking. I do not think the booster is leaking because I go out to the car an hour after I am done driving, pull the hose from the booster, and there is still vacuum. The engine runs great as well. The hose to the transmission is smaller and soft walled, not hard walled like the one to the booster. I am afraid that it is collapsing (it does not appear to be) or not giving as much vacuum as needed since I tee off of it.
 

·
Registered
Joined
·
6,163 Posts
Hi, you need to get a tee fitting with one large port and one small one for the trans the brakes shouldn't be teed from the trans lineif anything you could tee from the brake vac. but the trans line is to small for the brake booster to run on. John

Opal frost pearl metallic 67 coupe http://www.jps.net/binay/webdocs/febef75b01.JPG
also have a 95 opal frost pearl G/T BOSS edition convertible belongs to swmbo
 
1 - 6 of 6 Posts
Top