clutch master cylinder
#1
01-03-2006, 09:40 AM
clutch master cylinder
Ok, you guys have helped me many times and i greatly appreciate it. need some advice. my clutch master cylinder pushrod is worn and causing to much freeplay. I have already done the fork linkage which attaches to the pushrod. the plastic bushing then kept breaking because my pushrod opening
is worn from being metal to metal. i am looking at replacing the master cylinder. does not look hard. but i am reading that it is hard to bleed. can you tell me how to bench bleed, and where the best place is to get the master cylinder. napa has it for 70 with a 2 year warranty. 109 at the dealer. my master cylinder is fine. i have heard of a adjustable pushrod, but have been unable to find, and don't know if i could get the old one out.
thanks again
93 f250 7.3l idi diesel
4x4 manual.
is worn from being metal to metal. i am looking at replacing the master cylinder. does not look hard. but i am reading that it is hard to bleed. can you tell me how to bench bleed, and where the best place is to get the master cylinder. napa has it for 70 with a 2 year warranty. 109 at the dealer. my master cylinder is fine. i have heard of a adjustable pushrod, but have been unable to find, and don't know if i could get the old one out.
thanks again
93 f250 7.3l idi diesel
4x4 manual.
#2
01-03-2006, 11:07 AM
Clutch Cylinder Replacement
Welcome to the 93' Clutch. The original factory master cylinder rod has been a problem and as you mentioned the plastic clip that attaches the plastic rod lug to the pedal is also a problem. Bleeding the factory setup has also been a problem. My plastic lug on my rod broke at about 110k.
Ford has replaced the entire original master cylinder with a new cylinder design that uses a steel rod and lug. Unfortunately the new cylinder does not adapt to the original stainless hose going down to the slave cylinder so you need to replace it aswell with the new design. If you have access to a lathe you can machine your own pushrod out of steel with a steel lug. You will need to dissassemble the old cylinder for this, the rod is held on by a clip which can't be removed unless you pull the piston out. Make sure you keep the rod length EXACTLY the same as the 93' does not have any rod length adjustment. You also need to machine in a new step on the rod for the switch. The downside to this is once the the cylinder wears out you probably won't be able to get parts to rebuilt down the road so it may be best to just convert to the new cylinder now and be done with it.
The new steel lug design still uses the plastic bushing which allow the lug to come off the pin as the plastic bushing wears out. To solve this I drilled a small hole into the pin on the clutch pedal rod and put a dowel pin thru it. Now there is no way the lug can come off even if the plastic bushing wears out.
Bench Bleeding:
There is no bleeder valves anywhere on the system (bad design) In theory the master cylinder has a spring and ball valve built into the main piston that should release any air to the reservoir; unfortunately this design does not work to well in practice and the only real way to get the air out is to bench bleed the entire master cylinder, hose and slave cylinder. Just un-install, stroke the cylinder while breaking the hose connections to bleed as necessary and then re-install as an assembly, i.e. don't break the hose connections once you have gotten all the air out. (I am assuming you have an external slave cylinder, if not this could get really ugly)
Another way to bleed is if you can get some pedal you can drive like that, I did that the first time I had a problem. The air does work itself out over time, but for me it took several months before eventually I got my full pedal back. The above obviously won't work if you can't get enough pedal to operate the clutch, your only option then would be to bench bleed. I would not recommend this.
Lastly, the replacement cylinder that Ford offers has a slightly larger piston diameter which will require a somewhat greater actuating force, this is the main reason I want to go back to my original cylinder one of these days. A couple of hours in city traffic and I can really feel it in my left knee. But more importantly because of the greater wear and tear on the actuator bracket that secures the clutch pedal and shaft, the bracket cracked on me causing the pedal shaft to move away from the firewall which resulted in my pedal going lower and lower. Check you bracket for cracking, especially near the pin where the master cylinder rod connects, also where the bracket bolts to the firewall. Instead of replacing the bracket I ended up doing a weld repair and beefed up the bracket in the areas where it cracked. Not sure what a new bracket is worth, probably atleast a $100 and it will probably crack just the same.
I have rebuilt my old cylinder with a new steel rod and am planning on re-installing it one of these days.
Happy New Year.
Ford has replaced the entire original master cylinder with a new cylinder design that uses a steel rod and lug. Unfortunately the new cylinder does not adapt to the original stainless hose going down to the slave cylinder so you need to replace it aswell with the new design. If you have access to a lathe you can machine your own pushrod out of steel with a steel lug. You will need to dissassemble the old cylinder for this, the rod is held on by a clip which can't be removed unless you pull the piston out. Make sure you keep the rod length EXACTLY the same as the 93' does not have any rod length adjustment. You also need to machine in a new step on the rod for the switch. The downside to this is once the the cylinder wears out you probably won't be able to get parts to rebuilt down the road so it may be best to just convert to the new cylinder now and be done with it.
The new steel lug design still uses the plastic bushing which allow the lug to come off the pin as the plastic bushing wears out. To solve this I drilled a small hole into the pin on the clutch pedal rod and put a dowel pin thru it. Now there is no way the lug can come off even if the plastic bushing wears out.
Bench Bleeding:
There is no bleeder valves anywhere on the system (bad design) In theory the master cylinder has a spring and ball valve built into the main piston that should release any air to the reservoir; unfortunately this design does not work to well in practice and the only real way to get the air out is to bench bleed the entire master cylinder, hose and slave cylinder. Just un-install, stroke the cylinder while breaking the hose connections to bleed as necessary and then re-install as an assembly, i.e. don't break the hose connections once you have gotten all the air out. (I am assuming you have an external slave cylinder, if not this could get really ugly)
Another way to bleed is if you can get some pedal you can drive like that, I did that the first time I had a problem. The air does work itself out over time, but for me it took several months before eventually I got my full pedal back. The above obviously won't work if you can't get enough pedal to operate the clutch, your only option then would be to bench bleed. I would not recommend this.
Lastly, the replacement cylinder that Ford offers has a slightly larger piston diameter which will require a somewhat greater actuating force, this is the main reason I want to go back to my original cylinder one of these days. A couple of hours in city traffic and I can really feel it in my left knee. But more importantly because of the greater wear and tear on the actuator bracket that secures the clutch pedal and shaft, the bracket cracked on me causing the pedal shaft to move away from the firewall which resulted in my pedal going lower and lower. Check you bracket for cracking, especially near the pin where the master cylinder rod connects, also where the bracket bolts to the firewall. Instead of replacing the bracket I ended up doing a weld repair and beefed up the bracket in the areas where it cracked. Not sure what a new bracket is worth, probably atleast a $100 and it will probably crack just the same.
I have rebuilt my old cylinder with a new steel rod and am planning on re-installing it one of these days.
Happy New Year.
#3
01-03-2006, 11:16 AM
#4
01-03-2006, 11:29 AM
Cylinder questions
What you will find in the junk yard for rods is probably not much better than what you got given that the plastic lug design was not very good.
If you get the new cylinder design and hose from Ford you probalby are looking at $200 to $300.
If you got time, are handy and got access to machine shop it only took me a couple of yours make a new steel rod. You will still need to remove the cylinder so you can dissassemble and replace the rod. If you got a lot of miles on the old cylinder it probably won't be worth it as the cups might go next and then you are looking at a new cylinder anyways.
The stainless steel hose might be something you could get from a junk yard to save yourself the -/-$100 that Ford charges. (Assuming you can find a truck that has been updated)
Don't forget to check you brackets for cracks.
You do not want to do this job twice so in my mind a new cylinder, and hose might be the best bet.
Good luck.
If you get the new cylinder design and hose from Ford you probalby are looking at $200 to $300.
If you got time, are handy and got access to machine shop it only took me a couple of yours make a new steel rod. You will still need to remove the cylinder so you can dissassemble and replace the rod. If you got a lot of miles on the old cylinder it probably won't be worth it as the cups might go next and then you are looking at a new cylinder anyways.
The stainless steel hose might be something you could get from a junk yard to save yourself the -/-$100 that Ford charges. (Assuming you can find a truck that has been updated)
Don't forget to check you brackets for cracks.
You do not want to do this job twice so in my mind a new cylinder, and hose might be the best bet.
Good luck.
#6
01-03-2006, 03:30 PM
#7
01-03-2006, 03:52 PM
93 Clutch problems
Just make sure the cylinder NAPA is offering fits your truck. If they are offering a unit similar to the new Ford replacement cylinder with the steel lug push rod then this new cylinder will have a outlet pointing directly to the front of the truck.
The outlet on the original Ford Cylinder (presumably the one you have righ now) was pointing down.
If the Napa cylinder outlet point toward the front of the truck then you will also need a replacement hose between the master and slave cylinders. There is no way I know off to adapt the new cylinder to the old cylinder.
Compare your existing cylinder to the proposed new cylinder before you spent the $70 at Napa.
Who knows, maybe Napa still sells the old style cylinder with the plastic push rod lug. I would not go for that.
The outlet on the original Ford Cylinder (presumably the one you have righ now) was pointing down.
If the Napa cylinder outlet point toward the front of the truck then you will also need a replacement hose between the master and slave cylinders. There is no way I know off to adapt the new cylinder to the old cylinder.
Compare your existing cylinder to the proposed new cylinder before you spent the $70 at Napa.
Who knows, maybe Napa still sells the old style cylinder with the plastic push rod lug. I would not go for that.
Trending Topics
#9
01-04-2006, 07:22 AM
#10
01-04-2006, 08:52 AM
Sounds to me like the aftermarket guys may have come up with an adaptor that lets you use your old hose connection on the new cylinder. That would make a lot of sense to me given the cost Ford charges for a new Stainless Steel braided hose.
To remove your hose from your existing master cylinder all you need to do is remove the little stainless steel cotter pin. Once the cotter pin is out you just pull and the hose fitting should come right out of the cylinder. It may take a bid of tugging as the rubber seal on the hose fitting has probably hardend over the years.
Does the new NAPA cylinder you bought come with a steel lug on the master cylinder actuator rod? Do they still use the plastic clip to attache the lug to the pin on the clutch arm? If they do I would strongly recommend that you drill a 1/8" hole and install a cotter pin so the lug can't slide off the arm when the plastic bushing wears out.
Mine separated the very day I had a very important meeting with one of my engineering clients and after that I said to myself I was not going to take another chance. Make sure you use a center punch to mark your drill hole before you start drilling. It is a bit tricky but a sharpe 1/8" drill bit and a battery powered drill and you should be in business in less that 5 minutes.
To remove your hose from your existing master cylinder all you need to do is remove the little stainless steel cotter pin. Once the cotter pin is out you just pull and the hose fitting should come right out of the cylinder. It may take a bid of tugging as the rubber seal on the hose fitting has probably hardend over the years.
Does the new NAPA cylinder you bought come with a steel lug on the master cylinder actuator rod? Do they still use the plastic clip to attache the lug to the pin on the clutch arm? If they do I would strongly recommend that you drill a 1/8" hole and install a cotter pin so the lug can't slide off the arm when the plastic bushing wears out.
Mine separated the very day I had a very important meeting with one of my engineering clients and after that I said to myself I was not going to take another chance. Make sure you use a center punch to mark your drill hole before you start drilling. It is a bit tricky but a sharpe 1/8" drill bit and a battery powered drill and you should be in business in less that 5 minutes.
#11
01-04-2006, 09:00 AM
thanks again hamberger
they are still using the plastic fitting, which is what mine was. it does come with the cylinder, which is good, since they are about $8 at the dealer. i know what you mean about drilling the hole. i bought my truck from fatherinlaw, and whoever worked on it did the same thing. the trouble for me came over time since it was metal to metal the end going into the master cylinder rod had worn in half causing my freeplay, i replaced the fork last year, but did not do the master cylinder rod. i may post again if i have trouble with the bleeding. thanks again for the help
they are still using the plastic fitting, which is what mine was. it does come with the cylinder, which is good, since they are about $8 at the dealer. i know what you mean about drilling the hole. i bought my truck from fatherinlaw, and whoever worked on it did the same thing. the trouble for me came over time since it was metal to metal the end going into the master cylinder rod had worn in half causing my freeplay, i replaced the fork last year, but did not do the master cylinder rod. i may post again if i have trouble with the bleeding. thanks again for the help
#12
01-05-2006, 07:34 AM
#13
01-06-2006, 03:29 PM
got it installed. very easy. thanks again hamberger. my eyeloop was so worn on the rod on master cylinder it was about to snap. could use any advice on bleeding after installing. i filled master and used the rod to push out fluid before installing on the line. and left overnight with the cap off. so tonight i hook up the rod and see what happens. bye the way i found the part at
oreilly's for 42 with lifetime warranty. it was the same manuf. and had the
exact same part # as my old one. I was very impressed. never tried them.
autozone $42 no warranty
napa $77 lifetime
junkyard $30
oreilly's for 42 with lifetime warranty. it was the same manuf. and had the
exact same part # as my old one. I was very impressed. never tried them.
autozone $42 no warranty
napa $77 lifetime
junkyard $30
Last edited by gbeach; 01-06-2006 at 03:32 PM.
#14
01-09-2006, 08:58 AM
If you didn't have to drain the line and the slave cylinder you should be ok with just hooking it up and any remaing little bit of air should work it self out over time.
Did you say the replacement cylinder you got from O'Reilly's is identical to the one you replaced, c/w same part number. If so, does it have a plastic lug?
Good luck with the bleeding.
Did you say the replacement cylinder you got from O'Reilly's is identical to the one you replaced, c/w same part number. If so, does it have a plastic lug?
Good luck with the bleeding.