upgrading your square with a hydraulic clutch

[HotRodPC]

I think think I see one of the dimples on a pic from the firewall of an 85 C20. It also looks like maybe a hole is there for the clutch master, but it's got a grommet in it and used for the orange wire that goes to the Th400 kickdown switch. The wire in this pic is laid up on the cowel since the motor and trans have been removed. But if you look to the left of the grommet, I think I see a dimple just outside the grommet with the single orange wire. Kinda makes me think that could be the same hole that would be used for a manual trans truck.

 

[highdesertrange]

I will take manual linkage any day over hydraulic. with hydraulic I can't feel the clutch like I can with mechanical linkage. just my opinion. plus I did the hiem joint conversion before they became available, boy I thought I invented something, until I read that guys have been doing this for years. highdesertranger

 

[HotRodPC]

I will take manual linkage any day over hydraulic. with hydraulic I can't feel the clutch like I can with mechanical linkage. just my opinion. plus I did the hiem joint conversion before they became available, boy I thought I invented something, until I read that guys have been doing this for years. highdesertranger

I totally agree with you. I raced with Z bar linkage Muncie and loved it. I wanted it for my 4x4 truck too, but I was set straight with it on a 4x4 and it makes perfect sense. With frame flexing and lifts etc, that will throw your Z bar linkage off to the point you don't get clutch disengagement, so for my 4x4, since I do have a hydro bell housing already, that's what I'm going to be going with. If it were a 2wd and I'd be racing, I'd be going Z bar without a doubt.

 

[Stewzer55]

Is the frame bracket removeable for the Z-bar linkage? I know I have an almost complete Z bar setup for my 88 but not sure on that part.

 

[HotRodPC]

Is the frame bracket removeable for the Z-bar linkage? I know I have an almost complete Z bar setup for my 88 but not sure on that part.

NO, it actually attaches to the top of the frame rail then carries across to the block or the bell housing depending on what bodystyle of the truck. Squares, the pivot ball is right at the bell housing. 60-66 it's on the block and pretty sure it is on 67-72 too but in a different locaiton of the 60-66. Cars also. This is why the blocks have 2 different bosses for mounting the Z bar pivot ball. Now the later small blocks, DO NOT have tapped bosses for Z bar clutch IIRC, but the bosses are still there.

 

[Stewzer55]

Sounds like I'm going Hydro, but I'm just going to adapt the old bellhousing to a hydro slave.

 

[GreaseDog]

Just came across some new information! Someone has taken the hydro pedals and dissected them, and adapted the measurements to a mechanical pedal.

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thanks go out to Josh Harmon(via Facebook) for the pedal modification information.

 

[bluex]

Sweet! So he added a plate to the pedal for the hydro clutch?

 

[HotRodPC]

Great add to this thread @GreaseDog. Looks like you edited it just fine to me.

 

[GreaseDog]

Thanks Richard! Lol

 

[HotRodPC]

Hey, who the hell you calling a Dick???

 

[GreaseDog]

Lol

 

[bluex]

In the middle of my swap now and trying to nail down how to hook my master to the mechanical pedals. I came across this picture of a master mounted up with nothing in the way. I thought I would be helpful to give an uncluttered look at the location.

 

[bluex]

Another good shot of the mounting location

 

[HotRodPC]

i've had several guys ask me about swapping a hydro clutch into an automatic truck, or a truck with a factory mechanical clutch. so i thought that this post could be useful in the future.

for starters, you need the proper 85-87 hydraulic belhousing. the hydraulic belhousing from an IFS truck may work, but the slave cylinder is on the wrong side. you'll also need the specific hydraulic clutch pedal assembly, and the support rods that go between the pedal pivot and the firewall. everything else is available, as they're wear parts. some parts may be tougher to find, but they are available. i've heard of guys having problems finding a hydraulic line to go between the master and the slave. IIRC they are available from Napa.

the studs on the end of the supports are used to mount the master cylinder. proper positioning of these support rods, and the master cylinder are critical to proper geometry and operation of the clutch. fortunately the wiper motors are positioned the same on all trucks in the same position away from the brake pedal, so you can use the bolts for the wiper motor as a refrence point to accurately drill the proper holes.

here are the measurements to locate the master cylinder and the support rods.

You must be registered for see images attach

on trucks 84 and newer, you will often find dimples in the firewall where the center of these holes will be, if you find them, you can just use them and drill the holes to the proper size and be done with it.

the measurements are courtesy of TJ (aka big83chevy4x4)

See Post #22 for further template info: http://www.gmsquarebody.com/forum/showpost.php?p=230533&postcount=22

I forgot all about this thread. Glad we have this info already. Thanks again. Germy @GreaseDog