67 GT 350 power brake issue...

Helping a friend of mine work on his 1967 GT 350.

The car sits for most of the time, he drives it about 1-2 times per month. It has the Kelsey-Hayes-type dual diagonal brake booster/master cylinder set-up. It looks like all of the vacuum hoses, etc... are correctly installed and not damaged.

When the car is first started, the brakes hardly work, although there is some braking - it is minimal. There is also a "whoosh" type sound from the area of the brake booster. As the car warms-up, the brakes begin to work normally and whoosh sound disappears. Are we seeing a brake bleed issue here, or? Please advise!

I'm a new member. You guys have a great site.

Thanks.

 

Hi Greg,

I'm going to check the hose(s) next time I work with the car. I remember checking them and they seemed to be o.k. The booster/master cylinder assembly is not old - less than a year old (rebuilt) by a reputable source I've used on my Mustang.

Thanks for your help.

Regards,

Juan

 

The fact that the system works well after it heats up is the most puzzling to me. This is why I decided to get additional opinions!

I have a bone stock '67 GTA (289 4V, C4) with the same brake system (had it since '75) and when the diaphragm goes - it goes! No working when it heats up - it just goes.

I've checked the vacuum hoses and the vacuum and both are good. No splits or breaks, and the vacuum level is normal for a 271 hp 289.

Does anybody have a good rebuilder or source where we can have the unit rebuilt? It's an original Midland unit. My friend says it is about 3-4 years old (since it was last replaced/rebuilt).

Thanks gentlemen for all of the information and suggestions.

This a great bulletin board!

 

Okay, had a chance to discuss the issue with my friend. He recalls having the booster rebuilt and he found the receipt. It was rebuilt in April of 2006. The unit was rebuilt by a company in Upland, California (near Los Angeles) called Karps Power Brake Service. It's a Midland unit with the strap. The charge was $110.00 which included the master cylinder being rebuilt and the pedal rod adjusted. The cost included the unit being painted semi-gloss black. That's almost 7 years of service (albeit the car sits for about 80-90% of the time). I'm going to help him yank the sucker out later today, and take it to Karp's next week - they're about 15 miles from my office.

I'll report the results to you guys.

Here's a link to their website: http://www.karpspb.com/info.htm

Thanks for all of the input gents.

Juan

 

Thanks Roddster.

Would do, except there is no evidence of one on the booster. With the penchant for these units to fail over the past 40+ years, I fear that tag is long gone!

Thanks to all that have posted regarding this issue. I'll keep you advised as soon as we complete the project.

Regards,

Juan