Im having trouble getting the clutch sorted out Heres my setup: sbc/3 speed saginaw 40 ford master cylinder mounted on the firewall with old Ansen pedal 60's chevy pickup slave cylinder, I just made a bracket to mount it on the bellhousing. First, I ran 3/16" line from the master cylinder to the slave cylinder... After bleeding it, the pedal pressure was way to hard, and couldnt move the clutch fork far enough... So, I tried changing to 1/4" line...now, its not hardly moving the clutch fork at all. It seems like Im not having as much luck bleeding it now? The first time (with the 3/16"), when bleeding it, Id get a good burst of air and then the fluid would start to run out...Now, its not as much of quick "shot" of air or steady stream of fluid coming out... I cant see any leaks, and it seems to be holding the pressure...meaning, If I hold the clutch pedal down, it keeps the clutch fork held (what little it moves it)...where as if it was leaking, shouldnt the pushrod slowly be going back into the slave cylinder even while Ive got the clutch pedal held down? On the pushrod for the slave cylinder to clutch fork, I wasnt sure on the length, so I was using 2 small pieces of 3/8 threaded rod with a coupler to allow adjustment...so that I could figure out how long I needed to make it... I adjusted it out to where the piston in the slave cylinder is pushed all the way back in the bore and the other end is held tightly against the clutch fork... 　 Another thought... any opinions on the bore sizes of the master and slave cylinders? The master cylinder is 1 1/16 bore and I think the slave cylinder is 1" bore. What about 3/16" vs 1/4" line? I was thinking the 3/16" would cause greater pressure and changing to 1/4" would help...is that right? 　 I dont know... Ive never really messed with a hydraulic clutch setup before, so its kinda new to me... any opinions/tips?...maybe Im doing something obviously stupid, or overlooking something simple?
First off, see if there is a residual valve in the front of the master cyl. There should be, and that won't let the fluid return from the slave correctly. It's a disc shaped thing, stuck on the front end of the large internal coil spring inside the master. pull it apart, it's easy. Snap ring, and that's it... Secondly, the line size means nothing at all, you can run 1" if you wanted I just set one up; same chevy slave, but a chevy dual master. I did look at chevy hyd forks to compare my Olds fork length. The chevy truck fork has 2 spots to push against for some reason. The hyd slave setup pushes against the inner hole. My Olds fork hole was equal to the chevy outer hole. But mine works great. The 2nd hole on chevy fork most likely is for mechanical linkages I can get you some bore sizes in the AM, like what size master i am using with that slave....but get the master checked out first. Toss that valve out.
I think you will find out that the bores need to be the same. Line size should not make a difference as, the same amount of fluid displaced from the master when the pedal is pushed, will be pushed into the slave cylinder, the line size only adds volume of fluid within the system...
I don't know if this helps, but lots of early Mustangs with a T5 swap run a hydraulic clutch and I think they have much smaller bores than you are using. Seems like 3/4" is the norm. Typically a hard pedal with not enough movement is a sign of too big of a master cylinder bore.
If the master cylinder and the slave cylinder are the same size bore and you have all of the air bled out of the system, the piston in the slave cylinder will travel exactly the same distance as the piston in the master cylinder when you work the pedal, since you can't compress a liquid. Running a T5 from an S10 in my '38 Ford pickup with a 307 Chevy. I used the master and slave from a '70s Ford Courier (Mazda) pickup with a homemade bracket and a clutch fork designed originally for mechanical linkage. Works fine.
How far is the pedal moving the master cylinder rod? Make sure you have close to full cylinder stroke (don't bottom it out though) when the pedal hits the floor. I think that problem is combining with too large a M/C bore (in relation to the slave). That would account for the high pedal effort. If you ARE getting full stroke on the master, there's nothing more you can do about the pedal effort, as the only fix is a SMALLER m/c; which will move the clutch fork even less. Are any brackets flexing and using up your travel? How about firewall flex?
On my 31 I used an original 60's Dodge hydraulic clutch. It used a 1" master cyl. and a 1 1/8 slave cyl. I used the original clutch fork , bell housing from 60's Dodge pick up. every thing works just fine. Lee
Here is some info from my setup: The pic shows the guts to a Chevy "brake" master cyl. YouMUST remove the valve and the rubber washer when using a brake master as a clutch master. You need to do that! Measurements: - My chevy truck clutch master is 1-1/8" bore. -My slave is the same model as yours, I can't get to it to verify size. -My TOB fork measures 7-3/8" from the ball pivot in the bell, to where the slave pushes. -My stock Chevy truck hyd pedals measure 12-1/2" from the upper swing pivot, down to the center of the pedal pad. -Then, the master pushrod pivot is 2-1/8" down from the swing pivot. _this makes roughly a 6 to 1 pedal ratio. Now, Ansens were a simplified copy of Chevy pedals, but on hamb, some have said that "some" Ansens had two different pivot holes for the master cyl pushrod, to change the ratio. Look at yours.
Line size has NO effect on anything !! The Chevy M/C is 1&1/8 bore and the slave cylinder that Chevy used with it is 1&1/16. You need about 6 to 1 leverage on the pedal for reasonable pedal effort. Got the same setup in my T Roadster and it has a nice easy pedal. You do know that you need to swap the guts of the M/C side to side don't you? All the internal parts are the same except the brake bore has a check valve in it. Try working the release lever by hand with a cheater bar or etc. to confirm it works OK . The slave needs a straight line push on the fork to work corectly.
The bleeder valve needs to be at the top of the slave cylinder. Even some factory setups have acylinder that runs up hill the only way to get the air out is to take them loose and hold them so the bleeder is at the top.
A lot of interesting thoughts here. I can tell you on my hydraulic setup, I was told by an old circle track guy to cut the fork off fairly close to the bellhousing and then drill a new hole to put the slave cylinder shaft and ball into. The fork is really tough material. I needed to take it to a machine shop to have it drilled and they even commented it was a tough hole to drill. Mine works well.
Bob, interesting on relocating the slave push point. When I gave my measurements on the Chevy fork, I did not want to confuse the issue . That Chevy "big truck" hyd clutch fork has 2 different push points from the factory; I guess that fork was also used on other GM applications with mechanical linkages. When I converted my 55 Olds from mech to hyd, my Olds fork used the same length as the chevy's outer hole. But, the Chevy hyd setup used the inner hole, and that shortens the fork throw like you mentioned. I was concerned, but it works perfect for some reason, even though I am using a longer throw on the fork.
This is the slave unit from 1961 Ford Econoline, used with the swinging pedal assy.& master cyl.---Been using this setup since 1962.
i just fiished converting my f-1 ford to a hydralic set up, i used a wilwood clutch cylinder and a speedway motors slave cyl., all from speed way . every thing is working good except the throwout bearing is firm against the pressure plate. i am running a small block chevy, and a five speed . the trans is out of a 3rd gen camaro. i have narrowed it down to possibly the throw out bearing. i am using one for a chevy truck, and i am going monday to see if there is any dif. between the truck and one for a t-5 in a camaro. this has been a enlightning experiance
Thanks for all the info... F&J... I didn't put the residual pressure valve in, but I did put that rubber washer in... So, I ended up taking the master cylinder back apart to take out the washer and see if it made a difference... While bleeding it before I put it back on the car, I noticed that it had a small leak... Also, I thought maybe the slave cylinder was leaking and I couldn't tell because I had such a mess with brake fluid everywhere from trying to bleed it... So I rebuilt another master cylinder, and went ahead and replaced the slave cylinder...it's MUCH better now...I still don't think it's releasing the clutch fully, but I think I need to fool with the pushrod length some...and maybe get someone to help me bleed it some more... I think I got all the air out, but it wouldn't hurt to try it with a 2nd person rather than working the pedal with my left and and the bleeder screw with my right like I've been doing...
I would use 3/16" line.. Smaller master, smaller slave..1/4" line is sometimes hard to get all the air out.. And yes, make sure bleeder nut is facing straight up, even if you have to take slave out of it's mount to bleed it.....
Set up: Clutch slave piston positively pushed in all the way. Then when you make the pushrod, you take almost all the slop out of the TOB fork arm. Leave just a lttle free play before the fork makes the TOB start to push. You can fine tune the adjustment later to get proper free play. Master: make 100% sure there is a tiny bit of free play before the clutch pedal starts to touch the back of the piston. Adjust the rod to get at least a bit of play for now. Bleeding those 60s truck type GMs, normally is very easy, unless you looped a line back up or whatever. Some can be self bled by just barely moving the clutch master piston and keep watching the reservoir for a couple bubbles each time you barely move the piston. Other than that, if your ratios are good on the pedal and the TOB arm, it should be fine. I did not read back to post one right now, to see if you are sure you have the correct length TOB?
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