Brake pressure question- master, etc

[mikester]

When you say SS brake lines do you mean you replaced the rubber hoses with SS or do you mean all the hard lines ?
If you replaced the hard lines you might have a leak that you just havent found and its sucking in air. I just went through this with my 81 Malibu. The line from the master to the proportioning valve was seeping fluid at the line under pressure. Not enough to drip on the floor but with pressure on the pedal the tubing was wet at the fitting. Tightened it up and it started leaking at the threads. It was a pain in the butt to get that one line to seat.
I checked all the lines multiple times before I found that. If you have the calipers in right, your rear brakes adjusted, and it wasnt like that before, theres something youve missed and its something simple.

 

[85montess]

85montess, I just had a similar issue with my daily driver. You say you just installed front calipers. Is the bleeder screw on the caliper facing up or down? If facing down, you could have the calipers on the wrong sides. I made this mistake and chased weak pedal pressure for a week. Swapped the front calipers around and pedal pressure is back.

Thats a good point actually. I am pretty positive that they are on the correct side. I will of course confirm and dbl check this.

StreetBu ad Bitterman's comments need to be adhered to. If you have either of the issues they are describing, then your pedal will react as your describing.

Answering some questions though might shed some light on your issue though. Did the brakes work correctly prior to installing the S10 setup? If yes, then describe the parts installed on the front i.e. hose, calipers, pads, and were they new or used? Also describe how you bled the system. If no, then let us know so you can head off in a different direction.

To me though, your description sounds like you have air in the system. If the calipers and brakes are installed correctly, then you need to do some bleeding starting with the master cylinder, then onto the rears, and then finishing with the fronts.

Edit : forgot to mention - nice looking Monte !!

I had a buddy bring over his brake bleeder system. All the parts installed were new and the brakes worked before the new parts were installed, although it pads were worn, calipers were shot and rotors were in poor shape- so it all needed to be replaced anyway. I dont know that it would be a good benchmark to compare the before and after. Thanks for the compliment!

When you say SS brake lines do you mean you replaced the rubber hoses with SS or do you mean all the hard lines ?
If you replaced the hard lines you might have a leak that you just havent found and its sucking in air. I just went through this with my 81 Malibu. The line from the master to the proportioning valve was seeping fluid at the line under pressure. Not enough to drip on the floor but with pressure on the pedal the tubing was wet at the fitting. Tightened it up and it started leaking at the threads. It was a pain in the butt to get that one line to seat.
I checked all the lines multiple times before I found that. If you have the calipers in right, your rear brakes adjusted, and it wasnt like that before, theres something youve missed and its something simple.

Yes, I replaced the rubber hoses. The hard lines are all original. Sounds like I really need to just rebleed and start from the beginning.

 

[85montess]

Ok that makes more sense. You have a very low (squishy) brake pedal and poor brake performance. You shouldn't need a different master cylinder with those front calipers. Stainless steel lines won't change anything either. You either have a leak or have air in the system, no doubt. A leak should be very obvious, so I'm going to bet you don't have a leak. Next thing is air. I know you said there are no bubbles. Is the bleeder screw on the calipers at the highest point? In other words above where the brake hose attaches?

Okay, so I was able to check today under the car. It looks like the stainless steel brake line attaches to the caliper at the bottom. Not sure if this is the info you were asking about.

 

[Streetbu]

If the brake hose attaches to the bottom of the caliper, that means the bleeder is at the top which is correct. Do not bleed by starting at the wheels. Crack the lines at the master one at a time and bleed the master first. Once no air is coming out of the master, then move to the right rear wheel, left rear wheel, right front wheel, then finally the left front wheel.

 

[85montess]

If the brake hose attaches to the bottom of the caliper, that means the bleeder is at the top which is correct. Do not bleed by starting at the wheels. Crack the lines at the master one at a time and bleed the master first. Once no air is coming out of the master, then move to the right rear wheel, left rear wheel, right front wheel, then finally the left front wheel.

Okay awesome. Thanks for the reply.

 

[malibudave]

Did you adjust your rear shoes out against the drum?

This will cause a low pedal. This is the easiest fix.

That being said, are the rear brake shoe adjusters installed correctly? They are right hand side and left hand side specific.

When reversing your car and breaking, your rear shoes will adjust automatically out where they need to be. If the adjusters are installed on the wrong side, your rear shoes will adjust away from the drum instead of toward the drum.

 

[85montess]

Did you adjust your rear shoes out against the drum?

This will cause a low pedal. This is the easiest fix.

That being said, are the rear brake shoe adjusters installed correctly? They are right hand side and left hand side specific.

When reversing your car and breaking, your rear shoes will adjust automatically out where they need to be. If the adjusters are installed on the wrong side, your rear shoes will adjust away from the drum instead of toward the drum.

I don't recall specifically adjusting them no. I also don't remember having payed attention to right and left orientation. Can you tell from a picture? If so this is how mine look...

 

[malibudave]

At the bottom of the drum brake assembly there should be a "shaft" with a "star wheel" on it. The "star wheel" is the knob that adjusts the shoes out when braking your car in reverse. If they are not on the correct side of the car, they may adjust the shoes away from the drums.

Here is a youtube link that shows how to adjust your drum brakes.

Here is a g-body write up on rear drum brakes.

 

[85montess]

At the bottom of the drum brake assembly there should be a "shaft" with a "star wheel" on it. The "star wheel" is the knob that adjusts the shoes out when braking your car in reverse. If they are not on the correct side of the car, they may adjust the shoes away from the drums.

Here is a youtube link that shows how to adjust your drum brakes.

Here is a g-body write up on rear drum brakes.

even if it isnt the drums that video was super helpful and informative. thanks for that

 

[85montess]

Update: Found a little spot of rot in one of the rear solid brake lines. Fixed it, re-bled the brakes, and we are good to go!