zarcon

Hi, I have a stock 79 with 59,000 miles that I recently aquired and I am having difficulties figuring out what is wrong with my brakes.
When I first got the car, I noticed that the brake pedal had a very odd feel about it. It felt like there was air in the lines so the first thing I did was bleed out all the old brake fluid. I replaced it with regular DOT3/4 prestone. I found no air in the lines, but the old fluid was definitely due for replacement. Anyway, this action resulted in no change in pedal feel.
After driving the car more, I noticed that only the front right would lock up under hard braking. I also noticed that once in a while, the pedal would begin braking up high, though most times it didnt get hard until the pedal was very low, almost to the floor. I thought that this intermittent action might be due to a bad master cylinder. After I replaced the MC, I noticed no change.
Next, I decided to change the left front caliper and flex line. At this time I put in new rotors and pads on both sides. Again, no improvement or change has been registered.

The left front caliper is pumped directly out of the master cylinder on a 79, so I find it very odd that this caliper is not responding normally.
What should I do next? My instinct is to change the brake booster, but I don't know if that is wise. Is the problem more likely to be related to rear (drum) brake adjustment? Or does this seem like it could be related to the proportioning valve?

Thanks for the advice,
James

Fire85GSLSE

iTrader: (29)

James,

Swap out the brake booster. I had this issue and when I removed the brake booster I found that it was half full of brake fluid. I tried an 85 booster but was too large and hit the clutch master although I did mount it cocked and drove the car to find that holy crap feel has I almost went through the windshield. I ended up researching and measuring to find the 1980 SA booster to be a bit bigger than the 79 and better. So get you a new 80 booster (about $100) and that way you'll have a better system.

I have my 79 calipers (also fit repu if I remember right) if you need extra's. Was gonna list them up for sale anyhow.

zarcon

Thanks for the response. I will get a 1980 booster see if that solves it.

13x

I also had the same problem with my 79 that I picked up a couple/few months ago. I'd adjust the back brakes before spending anymore money. Try this, give the parking brake handle a couple or few clicks and I would believe you will feel the pedal come up. If this occurs its the rear out of adjustment. They do not adjust in the traditinal fashion. If you need further info I will be glad to get it for you

vmarx7@yahoo.com

iTrader: (37)

i too also had brake problems in my 79 that got me all bent out of shape.
i solved it by purchasing a crashed 85 SE for the suspension,trans, 4 wheel disc setup,replaced the booster & proportioning valve was alot of work switching everthing over but the results were well worth the effort.

Fire85GSLSE

iTrader: (29)

how did you get the SE booster to fit the 79 car? Or is yours an 80? 79 sa's booster and clutch master is way to close for an 85 booster to fit properly. I tried it and was about to weld it up and reposition it but went to an 80 instead.

zarcon

I ended up getting a reman 1979 brake booster locally. Last night I worked on the car. Before changing out the booster, I decided to look at the drums so see how they looked.
I ended up finding a siezed wheel cylinder on the driver's side. I ordered a new one from Autozone (only store around here was open at the time).
So I will be putting in that new wheel cylinder (or is it called a slave cylinder?) along with some new brake shoes.
If that doesnt solve everything, I still have that booster in hand.

Thanks for all the responses
James

vmarx7@yahoo.com

iTrader: (37)

i also tried using the SE unit but couldn't make it fit so i used it as the "core charge" and purchased a 80 reman.Sa's booster are a different size,shape & style.
eveything else that could be changed over/reto fitted was.

Fire85GSLSE

iTrader: (29)

Sorry to hear that. The 80 made such a difference over the brand new 79 booster I had on the car for 2 months. Once I felt the difference I sold the other one for 100.
I have a disk rear end with limited slip and it helps also!

13x

zarcon, sounds like you may have found a problem for sure.