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Any differences between brake pedals (vacuum brakes with an auto tranny) throughout the years?

handloader90

handloader90

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The truck I'm working on is a '79 K5, factory SM465 with mechanical linkage.

I'm leaning towards doing a hydraulic clutch swap using a kit from Novak.

I would have to get rid of my mechanical clutch/brake pedal assembly in order to use a Wilwood master cylinder and clutch pedal for the clutch portion.

Can I pull a brake pedal assembly out of any year/model of K-Truck and bolt it up in my truck without modification?
 
vac and hydro boost brakes pin hight is different on the brake bar were the rod clips on .

mech / hydro there is a difference also .

why not just adapt your setup use factory master and novar adaptor plate to take factory slave down on bell .
 
sweetk30 said:
vac and hydro boost brakes pin hight is different on the brake bar were the rod clips on .

mech / hydro there is a difference also .

why not just adapt your setup use factory master and novar adaptor plate to take factory slave down on bell .
Click to expand...

I didn't know you could use a factory master cylinder with a set of mechanical pedals?

How do you go about doing this? Seems easier and cheaper than what I planned on doing.
 
Will a brake pedal from an auto truck with vacuum brakes share the same mounting holes as a standard truck with vacuum brakes?

Is there a difference between the brake booster pushrod on the two vehicles mentioned about?
 
handloader90 said:
Will a brake pedal from an auto truck with vacuum brakes share the same mounting holes as a standard truck with vacuum brakes?

Is there a difference between the brake booster pushrod on the two vehicles mentioned about?
Click to expand...

Yes, the pedals and brackets will mount regardless of what sheet metal you started with. Keep the brake pedal matched to its style of booster and you will be fine, regardless of transmission type. The hydroboost brake pedal has a different pivot location and a return spring, everything else is identical.

I don't know off hand if the clutch pedal parts will swap exactly the way you want to, but it seems likely. That's the only snag that I can think of.

If you look through my Green Grendel thread, I have a bunch of pictures of the factory hydro clutch pedal setup and how I mix-n-matched to convert from vacuum brakes to hydroboost brakes. Parts are easily swapped and they bolted right into both of my mechanical-clutch-era cabs without problem.
 
After mounting my hydroboost unit the brake rod fit right onto the mechanical pedals. I think it'll work fine but it needs a stop to keep it from bottoming out.

There's a great mechanical to hydro thread I found on here. I'll post it soon. I'm doing the same thing.
 
wetoolowdingbangow said:
After mounting my hydroboost unit the brake rod fit right onto the mechanical pedals. I think it'll work fine but it needs a stop to keep it from bottoming out.

There's a great mechanical to hydro thread I found on here. I'll post it soon. I'm doing the same thing.
Click to expand...

You're converting to hydraulic clutch?
 
If at all possible I would like to keep my mechanical clutch/brake pedal assembly.

If I can hook that up to a factory reman K-Truck master cylinder that would definitely be ideal.

I'm keeping vacuum brakes, no plans for hydroboost in the near future.

Does a mechanical clutch pedal have the same amount of throw as a hydraulic clutch pedal from out trucks? Are the mounting holes for the clutch master cylinder push rod the same (same size, same placement) as the mechanical z bar linkage?
 
campfire said:
You're converting to hydraulic clutch?
Click to expand...

I've put it on the to do list, like it needs to happen soon lol.

I want to do it in a manner that uses my regular ol' mechanical bellhousing (I have x3 SM465's, x3 mechanical bellhousings). I don't plan on buying a bellhousing from a hydraulic setup, I would like to keep my mechanical pedals too vs. swapping in hydraulic ones.
 
handloader90 said:
If at all possible I would like to keep my mechanical clutch/brake pedal assembly.

If I can hook that up to a factory reman K-Truck master cylinder that would definitely be ideal.

I'm keeping vacuum brakes, no plans for hydroboost in the near future.

Does a mechanical clutch pedal have the same amount of throw as a hydraulic clutch pedal from out trucks? Are the mounting holes for the clutch master cylinder push rod the same (same size, same placement) as the mechanical z bar linkage?
Click to expand...

I don't know about the linkage, but I do know that the hydro M/C mounts in a hole that one of my early trucks was already using for its cruise control wiring harness. So I moved that harness and didn't hafta drill a new M/C hole. The other truck (the CUCV) had no such hole, nor did it have need of such. So I drilled out that one from scratch based on some online pictures of factory hydro setups. I made a cardboard template of my M/C before I started drilling.
 
wetoolowdingbangow said:
I know two guys who run hydraulic clutches with mechanical pedals. It will happen! It's just about setting it up right andirection making sure you have stops.
Click to expand...

Whatever info you have on doing this would be greatly appreciated. Links, pics, contact info or anything.

What the preferred way of adding a stop, just welding some flat stock in somewhere?
 
handloader90 said:
I've put it on the to do list, like it needs to happen soon lol.

I want to do it in a manner that uses my regular ol' mechanical bellhousing (I have x3 SM465's, x3 mechanical bellhousings). I don't plan on buying a bellhousing from a hydraulic setup, I would like to keep my mechanical pedals too vs. swapping in hydraulic ones.
Click to expand...

I was asking Eric, as I hadn't remembered him doing that swap. I guess his thread is moving too slowly for me to remember. :haha:

Like I said before, everything matches except possibly the mechanical clutch pedal. I'm not sure about that, but there aren't many things that can go wrong, you should be able to modify it to work if needed. Like Eric said:

wetoolowdingbangow said:
I know two guys who run hydraulic clutches with mechanical pedals. It will happen! It's just about setting it up right andirection making sure you have stops.
Click to expand...
 
I could mount the master cylinder wherever I wanted to vertically to get the right angles, measure the throw of the pushrod on the master cylinder and drill a new hole in the clutch pedal in the spot where it has the same amount of throw?
 
handloader90 said:
I could mount the master cylinder wherever I wanted to vertically to get the right angles, measure the throw of the pushrod on the master cylinder and drill a new hole in the clutch pedal in the spot where it has the same amount of throw?
Click to expand...

Yes. Remind me tomorrow and I'll go measure my hydro pedal so you know what the stock pivot distance is. Or you can just do the measuring & math with your own pedal and M/C if you prefer
 
campfire said:
Yes. Remind me tomorrow and I'll go measure my hydro pedal so you know what the stock pivot distance is. Or you can just do the measuring & math with your own pedal and M/C if you prefer
Click to expand...

I'd like to know what it is.
 
Been doing more research.

Found this GM P/N: 15592273

It's for the hydraulic actual clutch pedal by itself, I found one place online that says they have one in stock.

I started looking at pictures of hydraulic clutch pedal assemblies from our trucks and I think there is more to it than just the pedal listed above.

The mounting point for the push rod from the stock master clyinder is located on a piece of flat steel located near the upper part of the pedal, it doesn't run through the pedal like on a mechanical setup which means I might as well find a set of hydrauluc pedals which nobody seems to sell by themselves for a reasonable price, found a crusty set on eBay for like $375 I believe it was... I'll pass on that.

I'm gonna throw in the towel on trying to make my current pedals work.

Gonna order the following clutch pedal and master cylinder. I plan on reinforcing the firewall a little (probably just sheetmetal and pop rivets) where I mount the pedal listed above and I'll just find a brake pedal assembly in the junkyard.

Thanks for everyone's input on this thread, I want to make sure this truck is 100% though.

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