Clutch Master Cylinder Replacement

[mhall10407]

I'm going to have to swap the clutch master cylinder as oil is leaking in the firewall. I'm going to try to borrow a Hanes manual as I don't have mine anymore. From those of you that have already swapped one out what pointers do you have as things to make sure to do or not to do. If anybody has directions for swapping it out I would appreciate them as well.

Thanks,
Mike

 

[HI^C]

take line off, drain into container, remove cotter and pin from pedal under dash, remove firewall bolts, pull out as an assembly.

assembly the same, but you will bleed the system, bleed master prior to install helps, then bleed complete system from bleeder on slave after you are done.

 

[osagecruiser]

just did it on the 55..pretty simple just like hi c said......bleeds real easy..are you also replacing the slave cylinder?..i did both mine at the same time

osagecruiser

 

[GetsUThere]

2nd replacing both. My slave died shortly after replacing the master. Apparently that's a fairly common thing. Also, if you get fluid on any paint that you value, wash it off right away. If it's on there very long it'll discolor it and can eventually eat through it.

 

[Adventure Teq]

2nd replacing both. My slave died shortly after replacing the master. Apparently that's a fairly common thing. Also, if you get fluid on any paint that you value, wash it off right away. If it's on there very long it'll discolor it and can eventually eat through it.

Quickly eat through it, probably in about 15 minutes, be careful.

The biggest thing, as others mentioned, is getting it fully bled prior to install. Either submerge the porthole in fluid in like a small bucket or some kits come with a little fitting with a rubber line that goes back into the resorvoir, while pumping it of course. Basically whatever you have to do to get all the bubbles out before you hook it up to the system will help out a bunch.

Not so bad on a clutch system, but brakes can be a real pain if not bench bled fully.

 

[vt0u812]

(a little help with the bleed) i replaced my master yesterday and wished i read this thread prior to the instalation. Regarding the "porthole" and the bleeding operation. I assume everyone means in the inlet when you say porthole? I failed to bleed the system...just swaped out the master refilled it with oil and now the padel just seems to push down without presure (makes a squirting sound). Whats my best way to fix my screw up and get this system bled? Should i pull back off and submerge the inlet into a bath of oil? Im concerned i have I now pumped oil into the line?
I hate when i do stupid things - hoping someone can bail me out....thanks in advance for some words of wisdom.

 

[ludwig]

(a little help with the bleed) i replaced my master yesterday and wished i read this thread prior to the instalation. Regarding the "porthole" and the bleeding operation. I assume everyone means in the inlet when you say porthole? I failed to bleed the system...just swaped out the master refilled it with oil and now the padel just seems to push down without presure (makes a squirting sound). Whats my best way to fix my screw up and get this system bled? Should i pull back off and submerge the inlet into a bath of oil? Im concerned i have I now pumped oil into the line?
I hate when i do stupid things - hoping someone can bail me out....thanks in advance for some words of wisdom.

You can use a vaccume bleeder and bleed the system. Have one person hold the pedal down the other person operates the bleeder/ replace fluid. The most important of jobs in my opinion.

 

[vt0u812]

Sounds good - can you give some detaisl on what a "vaccuum bleeder" is? Is this something you purchase or can it be made?

 

[want2wheel]

When you filled the system up did you use "oil" or brake fluid? Brake fluid is the correct fluid to be used.

 

[vt0u812]

i used clutch fluid (gunk brand) - should i not have used that?

 

[dirtycruiser00]

I am actually going to be changing out both my master and slave next week. Did you guys replace the lines with the orignal hard and soft or did you go with one continuous flexible line from master to slave? thanks!

 

[ludwig]

Sounds good - can you give some detaisl on what a "vaccuum bleeder" is? Is this something you purchase or can it be made?

A vaccume bleeder is a tool. One would connect the right size flexabel tube to the bled screw, and pull a vaccume witch will pull the fluid and air out of the line, thus bleeding the system, either clutch or brakes. Your local parts store or the WWW will have a kit. Comes with all the parts and instructions you will need. Very handy tool to use!

 

[want2wheel]

Clutch fluid and brake fluid are the same thing. Either will work so keep going with it.

 

[dirtycruiser00]

DOT 3

 

[dirtycruiser00]

So whats everyone doing for lines? Original style (part hard and part flex) or flexible brake line the whole length? Thanks

 

[Fast Eddy]

x3 on replacing both unless you like working on your truck and finding something to do with the used fluid.

You don't need any special bleeder to bleed the clutch. Connect it all up, open the bleeder at the slave and let it drain through, keeping the master topped up, until there are no more bubbles coming out. It's called gravity bleeding.

If it's squishy after bleeding, and you bought the master at the auto parts, there's a good chance that it is bad, or the slave that needed to be replaced as well.

Brakes are much more complicated due to branches in the lines and a multi-compartment master. The clutch is way simpler.

 

[Pighead]

In my (limited) experience, clutch masters require little more than a gravity bleed ...

 

[vt0u812]

update - 1st...i'd like to thank everyone for their advice. I decieded to try the easy route without buying a bleeder pump and tried pigheads suggestion of a gravity bleed. After a few times of cracking open the bleeder in the slave, let it bleed a bit, tighten and pump the clutch (did this back and forth for about 4-5 times) i was able to get the air out of the line and now have full pedal presure.

 

[ZombieResponseUnit]

This might be a question for the Diesel comunity, but since this thread was going I thought I'd jump on it.

For about a year in the HJ45 I have had to pump my clutch. What I mean is the 1st push on the pedal goes to the floor, then 1 or 2 more pushes before it builds pressure and functions. Usually shifting only takes one push, if you've just built pressure. I've bled it 100 times w/o any difference, replaced the slave (because it blew apart, maybe due to very cold temps) and just replaced the Master cylinder. I still have to pump, but maybe it's better. I'm wondering if the slave/master are different for the HJ then those for the FJ?

 

[dirtycruiser00]

This might be a question for the Diesel comunity, but since this thread was going I thought I'd jump on it.

For about a year in the HJ45 I have had to pump my clutch. What I mean is the 1st push on the pedal goes to the floor, then 1 or 2 more pushes before it builds pressure and functions. Usually shifting only takes one push, if you've just built pressure. I've bled it 100 times w/o any difference, replaced the slave (because it blew apart, maybe due to very cold temps) and just replaced the Master cylinder. I still have to pump, but maybe it's better. I'm wondering if the slave/master are different for the HJ then those for the FJ?

Really shouldnt make a difference because its a closed system. Sounds like you still have air in the system or a leak. so you replaced both slave and master? did you replace the lines also?