Master Cylinder For Dummies.............dat B me.

[gadget73]

Any time something that might kill you or someone else if it quits is in doubt its a smart idea to have it towed before an accident happens.

[friskyfrankie]

Any time something that might kill you or someone else if it quits is in doubt its a smart idea to have it towed before an accident happens.

+1! I think he came to the same conclusion as we did since he wants it towed out there. As you say, nothing to fool with.

[87GrandMarq]

When the master cylinder went on my 90 mgm, the pedal had a lot of travel before the brakes engaged but did work fine. I ended up getting a close out deal on rockauto. It was a remanufactured master that had been sitting for some time. I was a little leery of using it but it’s been fine for about a year now. I think I got it for like 10 bucks.

[DerekTheGreat]

The clutch master cylinder in my K1500 is doing strange things similar to this. If I simply rest my foot on the clutch, it'll go to the floor with zero clutch disengagement. But if I quickly jab it to the floor, disengagement. Kind of fun to dink with, for now.

[gadget73]

problem with that is you may find one day it decides to just nope out on you. Not quite such a big deal with a clutch, can just jam it into neutral and then just rev match it to get home.

[DerekTheGreat]

Oh yeah, been there and done this. It's actually been acting up for months, but has gotten to this point. Parts store this week to order new master and slave cylinder for it. Surprised I got ~5 years out of this set.

[Mainemantom]

I know most repair places don't do this but I always bench bleed the replacement master cylinder before installation.

[DerekTheGreat]

Yep, I'm definitely doing that this time around. Also going to vacuum bleed the system. I did this job about five years ago and did none of that, which required me to jack the ass of the truck up far into the sky to be able to get all the air out of the clutch master cylinder.

[kishy]

Yep, I'm definitely doing that this time around. Also going to vacuum bleed the system. I did this job about five years ago and did none of that, which required me to jack the ass of the truck up far into the sky to be able to get all the air out of the clutch master cylinder.

This is a somewhat unique problem to your specific era of Ford truck. They are so notorious for being difficult to bleed that for some years and models, you can buy a complete set of master, slave, and clutch line, already filled and assembled which you just install all at one time.

For brakes, this level of insanity doesn't often come up, but bench bleeding the master (or at the very least, bleeding it on the vehicle but just with little tubes feeding back into itself) can help with some obnoxiously difficult trapped air and is well worth doing.

[DerekTheGreat]

This is for my GM truck, but I do wish that Ford was a stick. I ordered parts yesterday and they did have the complete assembly available. However, it was over $100 more than just the slave cylinder and clutch master cylinder so I decided to torture myself again.

[Toploader]

I know most repair places don't do this but I always bench bleed the replacement master cylinder before installation.

Tom, I have thought for years that masters had to be bench bled before install?? If not how in the world would one get a "pedal"???

[gadget73]

can do it easy if you pressure bleed them. Just shove fluid through the lines until it comes out the end. Master will mostly fill and mostly work, but there will usually be enough air stuck in it to feel funky. Vac bleed works too, but I've never had a lot of luck with that. Usually it sucks air around the bleeder so you can't actually tell when all the air is out of the system.

I've always just done the very manual process of pumping the thing with the little lines looped over to the reservoir until its bled, then pumping until the whole system is burped out. Takes 2 people but its pretty much guaranteed to work.

[Mainemantom]

I guess they figure the air will get bled out when the system is bled at the wheels. Master cylinder warranty is voided if bench bleeding is not done. Some mechanics rely on the power bleeder. or unfortunately gravity bleeding. When I hear gravity bleeding, I take the car somewhere else.

[DerekTheGreat]

...Vac bleed works too, but I've never had a lot of luck with that. Usually it sucks air around the bleeder so you can't actually tell when all the air is out of the system...

I was going to try to mitigate this by using teflon tape on the bleeder screws... Would be a first for me, but if it saves me some grief, I'm all for it.