The front brakes calipers were replaced with new 1970 Monte Carlo calipers. The calipers are getting the juice from the brake line but the cylinder will not fill up after a million pumps. No leaks were seen. What is the deal???
Guessing here, you’ve changed out the caliper ***embly, you mentioned Monte Carlo, are they properly sized for the master cylinder? While the ***embly was detached from the brake lines did the reservoir empty out? If so you may just have a large air bubble in the lines that can be a real challenge to get cleared out. Another possibility is any crud in the reservoir may now be keeping the cup seal in the master from sealing properly. Crack the bleeders and leave sit for a half hour check periodically and keep the reservoir full, 1/4 inch hose can be installed onto the bleeders to minimize the mess I’m also ***uming that the calipers are installed correctly? With the bleeders up? Funny as that may sound I recently picked up a g body that was parked for years because the brakes weren’t working, found new calipers were installed but upside down or on the wrong side whichever way you want to say it
Maybe you are misunderstanding me. The resevoir will not fill up but the juice is getting to them. I guess I could put juice with a syringe into the valve hole if I took the valve out but the pressure would still not be there to push out the piston.
So you're saying the master cylinder reservoir is just emptying no matter how much fluid you pour into it? Sounds like either you still have not put enough fluid into the system to expel all the air or you have a bubble caught between the master cyl and caliper somewhere. Do you know someone with a pressure bleeder that attaches to the reservoir cap? I have found these very useful in the past to move stubborn trapped air out of a system. https://www.amazon.co.uk/dp/B0GH66PR4G/?tag=atomicindustr-21
if the calipers haven't got fluid in them,then they have air. That has to come out. If your bleeding them is the bleeder port on the calipers pointing to the sky or ground ?
A 'million pumps' of the pedal would displace a ton of fluid. Where did that all go? As this seems to be a guessing game, perhaps the master is defective and what fluid has reached the calipers has got there by gravity and not master cylinder pressure. You should get a strong spurt out of the brake hose if you disconnect it from the caliper and depress the pedal. Perhaps the calipers are defective in manufacture? Like the hole for the inlet not drilled? It happens. Chris
Was it working before the calipers were changed? How do you know the fluid is getting to the new calipers? Is the master cylinder mounted higher than the calipers? With a helper behind the wheel to push the brake pedal, 1) open the p***enger bleeder screw ( should be on the top of the caliper) install a 1/4" clear plastic hose or rubber hose attached to the bleeder screw and the other end in a clear jar. NOTE: the hose should reach the bottom of the jar submerged in fluid to keep any air from being drawn back in. 2) have the helper push the pedal to the floor and hold it 3) close the bleeder and have the helper release the brake pedal 4) repeat this process till all the air is removed and only fluid comes out the hose 5) refill the master cylinder every two pedal pushes or as needed. When the p***enger side is full move to the drivers and repeat. If you do not close the bleeder screw while pumping the pedal, it will not draw fluid out of the master cylinder reservoir on the up stroke. Most system will gravity bleed if the master cylinder is higher than the calipers, thats why it was mentioned to open one bleeder at a time and wait. Those calipers will fit either side, they bolt right on, but do it wrong and the bleed screws will be at the bottom and you will never get the air out of them.
I would start by isolating each brake component. Start with the master cylinder. Remove brake lines from master cylinder and plug the ports with proper size plugs. Fill reservoir up and pump the pedal. If a firm pedal results and doesn't sink when held then master cylinder is providing pressure. If good and holds fluid then master cylinder is good. Next would be to isolate front and rear brake systems. Start by removing front brake plug from master cylinder and connect front brake line to master cylinder. Leave plug in for rear brakes on master cylinder. With reservoir full, pump brake pedal and check reservoir level. If still full, then front brake system is not where the fluid is being lost. If emptying, then front brake system is where the issues are at. Try the same test for rear brakes by removing rear brake plug on master cylinder and reinstall rear brake line. Remove front brake line on master cylinder and reinstall plug. Now see what happens when pumping the pedal. If reservoir empties then the problem is in the rear brake system. Using plugs is a fast way of determining where brake issues exist.
If the wheel cylinders won't fill with brake fluid then there is either trapped air, insufficient stroke in the master cylinder or a residual valve is installed backwards. If using a composite type res. valve/ proportioning valve ***embly, the valve may need to be reset so that both front and rear circuits are receiving brake fluid.
I forgot about the safety valve. Below is a GM proportioning valve, if the car has a GM factory valve similar to the one below and you pushed the pedal hard with no front brake pressure, the differential valve likely has closed off the from lines. It must be reset to center to open the front ports again. Equal pressure front and rear will reset it, or you can pull it apart and reset it. There are plugs made to hold it centered while working on the brake system. This is a safety valve incase the car looses front or rear brakes, it provides enough pressure to the working half to stop the car. To check for center alignment, a multi meter with a probe on the housing and probe on the brake warning light contact will show continuity if it's tripped. If the meter shows open, it's still centered.
Yup, pretty sure we’re misunderstanding, first we need to clarify what system, then define some terminology, I’m guessing an 80s GM from the Monte Carlo, the caliper is the slave cylinder, you have the inlet port the flexible brake hose attached to and the bleed screw which must be at the top when installed on the correct side of your vehicle. The “reservoir “ for the system is usually on the firewall generally on top of the master cylinder. When the calipers were removed it’s not unusual for some or all of the brake fluid to leak out of the system, when installing the new calipers, once the brake line is attached, the bleed screw can be cracked open, attaching a length of clear 1/4 “ hose to the bleed screw and the other end in a jar , fill the reservoir with new fluid and leave sit like in my previous post, once you have fluid dribbling into the jar close the bleeder and switch to the other side and repeat, then you can proceed to bleed the system of any residual air. A buddy will really be handy at this point, with hose still attached to the bleed and in the jar with some fluid in it, hose in the fluid , depress the brake pedal and hold down, crack open the bleed allowing air and fluid out, still holding close bleed, pump brake a couple times a repeat until nothing but fluid comes out of the hose, switch sides and repeat until you get a solid brake pedal.
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