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Hi there, new here. Replaced master cylinder and booster after having the brakes go out. Seemed to be going pretty good, did not bench bleed (have read so many threads on whether or not bench bleeding is necessary). I got the back wheels to bleed pretty easily. Nothing moving out of the front. I have found a couple of threads that report this issue, but the solution is unclear. I traced back out of the MC. It looked like no fluid was moving into the line for front brakes. I took it off and pushed it in a few times and was able to force a bit of fluid through the front valve, but it mostly blasts out the rear valve. Can someone provide some clarity here? I'd go to start looking at the lines, but it really seems like the flow coming out of the MC is the issue. Thank you!
No distribution switch. I would look into the lines, but the problem is that fluid is not moving out of the MC. It's not even getting into the line. Going to attempt a bench bleed to force fluid out of the MC through the front brake valve (which I already *sort of* did, but let's make it official). But why? Why a struggle to get fluid into both lines? Is it a leveling issue? Do I have a bad MC? Again - I've seen this issue come up on a few threads, but I never saw a clear solution.
Hi there, new here. Replaced master cylinder and booster after having the brakes go out. Seemed to be going pretty good, did not bench bleed (have read so many threads on whether or not bench bleeding is necessary). I got the back wheels to bleed pretty easily. Nothing moving out of the front. I have found a couple of threads that report this issue, but the solution is unclear. I traced back out of the MC. It looked like no fluid was moving into the line for front brakes. I took it off and pushed it in a few times and was able to force a bit of fluid through the front valve, but it mostly blasts out the rear valve. Can someone provide some clarity here? I'd go to start looking at the lines, but it really seems like the flow coming out of the MC is the issue. Thank you!
New MC and booster.
Let me see if I have this right:
You didn't bench bleed it, and now you're having problems getting fluid to the front brakes?
I bled it, yes. UPDATE: returned the MC, got a new one - SAME PROBLEM. Only one valve pumps fluid. I know this from putting it on the vice level and pumping it. This tells me there must be something I'm missing, some step or information. The front valve (which goes to back brakes) works great, flows well. Bone dry out of other valve. What is going on?? I pumped long enough to empty the front tank and refill it once. I'm getting very little, if any, bubbles out of the big tank.
New MC on the vice to very officially bench bleed. Dripping front valve Bone dry back valve
Is your truck all drum brakes or does it have disc up front? You should have a brake pressure differential valve for disc and drum. If you have disc front, you should also have a metering valve. What year is your truck and is it f250 or f100? Here is a good link on the brakes https://www.fordification.com/tech/propvalve101.htm
So to bleed the master cylinder you need to actually do it in two stages. First you bleed the front bowl by only moving the plunger about half inch till you get fluid moving. There is a couple of guys on youtube (pole barn garage and junkyard digs) that have done this and you can see how it's done. It's very informative to be honest.
Got it to work. I, unfortunately, do not have a good answer for what went right. The valve that was dry eventually just started leaking, then flowing. Pump a lot I guess. Thanks all for the help!
