Difference between hydro and vacuum brake pedal assembly?

[erasedhammer]

I am trying to find a manual clutch/brake pedal assembly, but there are not that many for sale. I found one, but the seller says they do not know if it's off a hydroboost or vacuum brake truck.

What are the physical differences between the hydroboost and vacuum brake pedal assemblies?

Pic of item being sold:

 

[cucvrus]

That looks like it will work. The push rod to the hydro-boost hooks up the same way. Not 100% positive but it looks the same.

 

[Evil Dr. Porkchop]

I have a pedal bracket in my m1028 from a hydraulic clutch, vacuum boost truck. I installed one in a CUCV blazer too.

As I remember the pedal bracket has 2 mounting studs that need to be cut off, because they’re already on the booster side. Also the vacuum brake pedal was different so swap your original pedal to the bracket and cut down the pad to match the size of a manual pedal.

 

[erasedhammer]

I have a pedal bracket in my m1028 from a hydraulic clutch, vacuum boost truck. I installed one in a CUCV blazer too.

As I remember the pedal bracket has 2 mounting studs that need to be cut off, because they’re already on the booster side. Also the vacuum brake pedal was different so swap your original pedal to the bracket and cut down the pad to match the size of a manual pedal.

Cool, as long as it doesn't require crazy modification to fit and work, works for me.

 

[erasedhammer]

That looks like it will work. The push rod to the hydro-boost hooks up the same way. Not 100% positive but it looks the same.

Got word that the pedal assembly is off a mechanical clutch setup, can it still work for a hydraulic clutch?

 

[cucvrus]

Got word that the pedal assembly is off a mechanical clutch setup, can it still work for a hydraulic clutch?

I would be lying to say I even knew. Do what you have to do. Find a stick shift truck in a salvage yard and go at it and salvage every part. I could tell you what year or model them pedals came from or would fit into. With an idea and a welder just about anything can be made to work. I stay as stock as possible and avoid the guess work. That is years ago that I dealt with these trucks. I don't want to guess.

 

[Black Ops]

Got word that the pedal assembly is off a mechanical clutch setup, can it still work for a hydraulic clutch?

If you want a hydraulic clutch setup you’ll want to find a factory assembly, they are not easily converted from a manual linkage setup. Hydraulic was used in 1985 and up square bodies.

 

[erasedhammer]

I would be lying to say I even knew. Do what you have to do. Find a stick shift truck in a salvage yard and go at it and salvage every part. I could tell you what year or model them pedals came from or would fit into. With an idea and a welder just about anything can be made to work. I stay as stock as possible and avoid the guess work. That is years ago that I dealt with these trucks. I don't want to guess.

Yeah, I just can't seem to find any at any junk yards. Nothing pre 1995 in any pick n pulls. Very little chevy's. It would be surprising to find any brand manual truck here.
Which leaves me trying to source parts on craigslist/ebay unfortunately..

 

[cucvrus]

I am currently checking with a friend. He did the stick conversion and was quick to switch it back. I sent him a text to see if in the unlikely event he would still have the pedal and linkage parts. His was a manual bell crank clutch no hydraulic. The low gear was too low and hi was the same as the TH400 he changed it back after about 6 months. I will advise. I think he may have everything. Maybe if your Lucky.

 

[erasedhammer]

I am currently checking with a friend. He did the stick conversion and was quick to switch it back. I sent him a text to see if in the unlikely event he would still have the pedal and linkage parts. His was a manual bell crank clutch no hydraulic. The low gear was too low and hi was the same as the TH400 he changed it back after about 6 months. I will advise. I think he may have everything. Maybe if your Lucky.

If he has other parts that would be great, I am looking for a hydraulic clutch setup though.

 

[cucvrus]

That I know he does NOT have. I was at the YOUPULLIT when we cut all the parts from the frame with a Sawzall. So I know he has the old bell crank setup and I had new bellhousing balls. I still have the hydraulic clutch bell housing for the Chevy truck. I will sell that but as far as other pars. I have sent all that old stuff thru the shredder as scrap. Let me know if you need anything else. I also have a 2WD SM465 granny low transmission yet. But nothing else in manual. Good Luck.

 

[Recovry4x4]

Why do you require hydraulic clutch? If it's because that's what you heard was best, you may need to revisit that. The Porkchop physician was spot on with the difference in brake pedals. The hydroboost pedal also sports a small return spring. Converting mechanical to hydro clutch requires much Fab work. Very little was the same. I've had the age old z-bar mechanical stuff on my CUCV for years and it works great. Don't sell it short, worked fine since the mid sixty's.

 

[cucvrus]

My friend still has all the linkage and parts we removed from the bone yard truck. It is available. I ask him to give me a price and if he has everything. I seem to think he does. I will keep you advised. It is the old school clutch. No Hydraulic.

 

[erasedhammer]

Why do you require hydraulic clutch? If it's because that's what you heard was best, you may need to revisit that. The Porkchop physician was spot on with the difference in brake pedals. The hydroboost pedal also sports a small return spring. Converting mechanical to hydro clutch requires much Fab work. Very little was the same. I've had the age old z-bar mechanical stuff on my CUCV for years and it works great. Don't sell it short, worked fine since the mid sixty's.

I've driven a few mechanical clutch vehicles, and the hydraulic setups are always easier in terms of force.
Especially going in a 1 ton truck with clutch much heavier than say a Jetta.

 

[erasedhammer]

That I know he does NOT have. I was at the YOUPULLIT when we cut all the parts from the frame with a Sawzall. So I know he has the old bell crank setup and I had new bellhousing balls. I still have the hydraulic clutch bell housing for the Chevy truck. I will sell that but as far as other pars. I have sent all that old stuff thru the shredder as scrap. Let me know if you need anything else. I also have a 2WD SM465 granny low transmission yet. But nothing else in manual. Good Luck.

I was simply looking at the advance adapters bell housing since it's an external slave cylinder that sits in the driver's side. Haven't looked too much into oem housings simply because they are harder to find.

 

[cucvrus]

I have an OEM bell housing if you or anyone wants to buy one. It is the Hydraulic one. Unfortunately the rest of the truck is gone to the shredder.

 

[Recovry4x4]

I've driven a few mechanical clutch vehicles, and the hydraulic setups are always easier in terms of force.
Especially going in a 1 ton truck with clutch much heavier than say a Jetta.

That is true. Unless you're going to some high performance Borg and Beck style clutch, the factory one ton clutch is pretty easy. I've got bad knees and I manage fine. Your mileage may vary.

 

[erasedhammer]

I have an OEM bell housing if you or anyone wants to buy one. It is the Hydraulic one. Unfortunately the rest of the truck is gone to the shredder.

I know there was some drive shaft clearance issue with the stock slave cylinder setup? That was the only reason I found the advance adapters bell housing, it relocates the slave cylinder so theres no clearance issues with the front drive shaft.

 

[Evil Dr. Porkchop]

Sounds like you’re installing an NV4500, not an sm465? The later NV4500 chevy trucks have the internal slave setup which has no clearance issues. That’s what I have in m1028.
The earlier NV4500 chevy trucks have the slave cylinder on the passenger side which I’ve also heard will have clearance issues with the driveshaft.

 

[erasedhammer]

Sounds like you’re installing an NV4500, not an sm465? The later NV4500 chevy trucks have the internal slave setup which has no clearance issues. That’s what I have in m1028.
The earlier NV4500 chevy trucks have the slave cylinder on the passenger side which I’ve also heard will have clearance issues with the driveshaft.

Yeah, sorry, nv4500.
I am a bit skeptical about the internal slave setup. That's why I'm going with the advance adapters bell housing which allows external slave on the driver's side.