Alright short and sweet 83 Z28 swapped in 350 and th350 that runs great. My brakes have been plaguing me for months now I have replaced front pads, rotors, calipers, rubber lines, Back shoes and hardware, and recently put in new booster also. The problem lies in my master cylinder I am on my second one and I do not know what I am doing wrong but I just cannot get it to bleed properly. I have been at this all day now and for some reason I still get a geyser in the back reservoir no matter how many times I sit there and pump. It is level the fittings are tight with hoses running nicely back into the top submerged in fluid. Can we bleed our master cylinders on the car if they are at an angle because it seems some people say yes and others say no. Any advice at all on why this is happening now in the second new master I have gotten I really want to drive my car thanks.....

 

Yes. Get an old lid, create holes in it to run the hoses through and pump full length strokes.

You also didn't actually say what was wrong with the brakes. And the geyser is a problem why? Because it's aerated?

 

After connecting the bench bleeder kit to your master cylinder you will pump the peddle slowly and to the floor. After all the air is out of the master cylinder have someone hold the brake peddle to the floor while you connect the lines.

 

The problem with my brakes has been I have not been able to get a solid pedal I can stop but it will go all the way to the floor. I will give bleeding on the car a try and see what I come up with...

 

rear drum brakes?

if so, are they adjusted properly?

 

 

I agree about the drum brakes. also, if bleeding the master on the car is too much of a problem you can always bench bleed it. Brakes can be a PITA, good luck

 

No reason for fluid to be a gyser when bleeding the master cylinder. Just pump the pedal slowly and it shouldn't be a problem. Ive done master cylinder bleeding on the car prob 5 times in the last 4 years (upgrades) everytime with the cover off and no gyser unless i pump to fast bc i forgot about having the cover off. Only real way to get the pedal to the floor is to have air in the system or a huge fluid leak. Remember that the front brakes do 70% of the stopping so if its going to the floor then air is the problem. I bled my brakes more times than I can count and always bleed from the farthest point . Rear pass, rear driver, front pass, front driver. Unless the master is bad even without power brakes u should have a firm pedal as long as their is no air in the system or leaks.

 

Thanks for all the replies guys I have 2 very long days of work ahead of me so I won't get back to the car tell Thursday but to answer a few questions yes the back brakes are adjusted correctly so I will give bleeding the master on the car a try and see how it goes what was happening on my last master is that the front port would never give me a solid stream of fluid would just spray lots of air out and I believe that in turn gave me the geyser im still getting....

 

If it was just the front port (thats the rear brakes) then I would also look at the seals that the reservoir has that pushes into the master. They can go bad and most of the time when you get a rebuilt/new master they don't give you a new reservoir or seals. could be drawing in air from around the reservoir as the plunger is pressed.

Could also be the inside of the master the plunger oring for the front port was all chewed up from pitting inside the master bore. water in the lines causes pitting in the aluminum which chews up the seal causing brake issues. Rebuilt masters I don't believe they clean up the bore at all, basically just change the seals and call it a day. Thats why they say its better to buy a new master as there won't be a chance of pitting and chewing up the new seals but new masters are like 4x the cost of a rebuilt.

remember after you bleed the master and hook up the lines you need to rebelled the whole system. Now would be a good time to throw in some hi temp silicon fluid. Silicon fluid can never absorb water so the fluid never really goes bad. But u can't mix it and the whole system need to be replaced. But since your doing it away you might as well.