The other day I was getting in the vette to drive her to work. I pulled out of the driveway and heading down the street I hit the stop sign and noticed the brake pedal went all the way to the floor board and the brake light came on, but the brakes did grab but barely. I continued to the gas station around the corner cautiously because I was low on fuel. Once I pulled in I checked the brake fluid reservoir and the front reservoir was almost completely empty. I went in and purchased some brake fluid and filled it to the correct level. After fueling up I pumped the pedal a bit and it pumped up but then seemed to give out again. I took her home and parked her until yesterday when I was able to look at her. I jacked up the front end so I could see under better and had someone pump the brakes but nothing seemed to be leaking out. I looked in the reservoir again and it seemed fine this time. I also slowly pumped the brake pedal with the reservoir lid off as to get any air bubbles out. I then drove it around the block and noticed that when I braked hard it went all the way to the floor it would also pull to the right.

With all this being said can anyone give me some advise or pointers in where I should start looking? Thank you in advance...

 

Well first off you said it pulled to the right, so that says that side is the side that is working. I would start by checking the lines on the left side and if you are not loosing fluid, then you have an air issue that just now popped its head up. Bleed them, starting with the left side. and look your calipers over real well and make sure they are pumping up correctly while you have the wheel off. I am sure there will be other suggestions, Good to see another Okie on here!

 

How empty was empty in the master? You may have to pull it and bench bleed it first. Start by replacing all the soft lines, how old are the calipers on the car, they may need to be replaced too? And re bleed the entire system.

 

OK, it is snowing here as you know 81pilot (good ole oklahoma in March right) but I will check out what you said hopefully mid week.

Grumpy_427 - The back reservoir was full and the front one probably had an 1/2 inch of fluid in it. I have never bench bleed anything before so I will have to look into that if that is going to be the case.

 

Does your car have stainless steel calipers? If not, I would probably start by installing four new calipers, along with new flexible lines if they've never been done. After all, the car is thirty years old.

 

See my recent (today) post where I bled/filled my brake system. If you decide to bleed the full system first (requires only two people and BEER) before you remove/replace the calipers, give that procedure a try. DOT 3-4 fluid is what I used since I don't run silicone fluid in my C3 (perhaps I should but I've not made that leap yet).

These systems need bled every two years at the minimum. I let mine sit five (5) years which is WAY too long.

Let us know how it all works out. NOTE: Van-Steel has a great rebuild service (Clearwater, FL).

 

Well you may not have to pull the master, it sounds like you had plenty of fluid in there. But you have a leak someplace?

 

She does not have Stainless Steel Calipers. What would be the benefit of Stainless Steel ones vs OE ones from part store? The lines look stock as well.

I read the post about bleeding the brakes, thank you for that info. I will check into that this week, maybe have to wait til next weekend until I can get some help.

It would seem there is a leak some where but I could not tell you where. Maybe doing the bleed will show me all of the areas and i can tell where it is coming from.

Here is a question about the brake fluid reservoirs. It is broken into two halves inside. Is it front/rear or driver/passenger or just random to which front/back half controls fluid for what. As you can probably tell I am not that familiar with braking systems. Just break pad jobs, and I did have to replace a reservoir once on an old truck I had.

 

Get yourself one of these and you'll never look back. Makes bleeding brakes an easy, one person job.



I'd also recommend O ring calipers over the shet you'll find over the counter. VBP offers a good set. They'll keep your calipers from sucking in air even if you do have a bit of runout.

 

Check the inboard sidewalls of each tire. If a caliper is leaking, the fluid often ends up on the wall of the suspect tire/wheel. When I purchased the rear stainless sleeved calipers from VB&P, I also replaced the rear lines that connect to the calipers as mine looked original (rusty and tired). That is often the place where you will see your leak (the tire surfaces). I tried rebuilding my calipers and quickly realized that it was beyond 'my job description' as the stainless sleeved calipers that I could buy from VB&P or Van-Steel far exceeded what I could manage with a simple rebuild kit (ie. without sleev'ing them). Given the age of the calipers (if original), they likely need stainless sleeves if they have never been rebuilt AND leaking. If you choose to replace calipers, I'd recommend doing them in pairs (ie. if LR is leaking replace both the LR and RR calipers).

NOTE: Stainless calipers often refers to cast iron 'Moraine' castings that have been rebuilt and stainless sleeves have been inserted in the bores of the calipers (each half caliper has two bores). The stainless material is less susceptible to corrosion than the naked cast iron... from what I have read anyway. Still, it is highly recommended that you bleed the system every 2 years if running DOT 3 or DOT 4 fluid. I've heard DOT 5 silicone fluid does not collect moisture as much as the older DOT flavors.

 

I agree. Another thing to look for is run out. If your rotors have a bit of wobble, the calipers can suck some air and make the brakes hit the floor fairly quick.

 

Excellent point. If the run-out (on rear wheels) is excessive, it is a good idea to have the rear bearing assemblies rebuilt since if there is excessive run-out it is a symptom of greater (rear) bearing assembly issues. I remember when I was diagnosing what appeared to be an annoying 'squeak' coming from the rear of my '69 L46, turned out that BOTH spindles were worn/critical and t-arm rebuild was imminently necessary. Van-Steel did a great job on them.

I think the half-shafts were shot also. AGE is a terrible thing in a C3.

 

Runout will put air in the system, but it will not make the fluid level decrease. You have a leak and there is only two options. One its going on the ground. Two its going in the brake booster.

First thing since you said you couldn't see any fluid leaking, take the two bolts loose that hold the master to the booster and move the master slightly so you can see if that's where it is going. If it is replace the master and booster because once you get fluid in the booster it will probably fail soon anyways.