SM465 manual clutch to NV4500 hydraulic clutch

[DaisyLDG619]

So for some background. I have a 76 K20 with a SM465 and a manual clutch behind a beefed Up 6.2 diesel hybrid. I'm taking it out for a NV4500 to try to get the highway gear. The bell housing and clutch is on. My NV is external slave and I'm wondering if anyone has used the stock spring style clutch pedal and converted it to work with a hydraulic clutch master and if so how? If this has been posted before please let me know. I just know I'll be damned spending $600 on a conversion "kit" when myself it appears as though I can weld some braces for the master and drill a hole in the pedal for the master rod and call it a day. Any advice is appreciated

 

[Redfish]

Don't know if you are aware but GM started using a hydraulic clutch pedal assembly on the later square bodies. My '87 has a hydraulic system. Perhaps you could see about getting some of those parts?

If you need me to, I can try to get some pics of the pedal and anything else in my truck.

In fact...getting an under the dash pic was more difficult than I expected. Hope these help.

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[nvrenuf]

GM started using hydraulics in ‘85.

Advance Adapters makes a bracket to put a slave cylinder on a mechanical bellhousing, not sure if they offer anything for the pedals.

 

[DaisyLDG619]

Redfish
I was looking into that but everything I can find factory parts wise doesn't show a different pedal. Though my cab does for some reason have the dimples for a slave even with it being as old as it is. So I guess I'm trying to figure out if the pedal itself changed or if they just changed everything outside the pedal and put a hole in it. Plus a factory hydro for these trucks seems just about impossible to find.


Nvrenuf
The bell housing for my NV4500 is an external slave and fork already and these Bell housing are like gold so I'd prefer to keep it and go hydro

 

[Redfish]

@DaisyLDG619 I can possibly try to get some better pics of the pedal, it was more difficult than you might think to get those pics. I am just pointing the camera upwards and then deleting the worst of them.

I don't think it should be that difficult to get the factory hydraulic components. The guy I bought this truck from installed a new slave right before I got it and I replaced the master 13 months ago. I got the new master cylinder from O'Reilly Auto Parts. They didn't have it in stock at my local store but they had it here the next day from a store in Houston.

I couldn't remember what year GM switched to hydraulics but I think @nvrenuf is correct, it was around '85. Try shopping for the master and the slave cylinder for a 1986 model. You may have to piece it all together and you may have to run your own tubing but it can be done.

 

[DaisyLDG619]

@DaisyLDG619 I can possibly try to get some better pics of the pedal, it was more difficult than you might think to get those pics. I am just pointing the camera upwards and then deleting the worst of them.

I don't think it should be that difficult to get the factory hydraulic components. The guy I bought this truck from installed a new slave right before I got it and I replaced the master 13 months ago. I got the new master cylinder from O'Reilly Auto Parts. They didn't have it in stock at my local store but they had it here the next day from a store in Houston.

I couldn't remember what year GM switched to hydraulics but I think @nvrenuf is correct, it was around '85. Try shopping for the master and the slave cylinder for a 1986 model. You may have to piece it all together and you may have to run your own tubing but it can be done.

I have the slave from the 94' trans and was contemplating even using the master from the same truck (just new) and I do appreciate the pics. I did find a pic from another forum but the master rod angle looks lightly concerning. Granted I've always done mechanical so when the rod is off at an angle to push straight it just doesn't look right to me

 

[squaredeal91]

The chevy master sits crooked in the firewall. On my 91 with factory Hydraulic clutch I made a special bracket to use the Ford clutch master because I have a zf5 behind my Cummins. However m interested in this thread because I am possibly this summer going to try putting an NV4500 in my 78 and needing to do a Hydraulic pedal conversion from auto. I have transmission and mechanical clutch pedal assembly to get me started

 

[SquareRoot]

I converted my 85 from a th400 to a nv4500 recently using all factory parts except for an AA bellhousing. Upgraded to hydroboost in the process. I highly modified my pedal assembly with stainless steel oversized pins and spherical bearings/rod ends to forever get rid of the thin plastic bushings and rusty cross pins. I have several OEM clutch pedal assemblies both vac and hydro.

I'm interested in the difference between the earlier mechanical pedal assembly and the 85-87 hydraulic units. Perhaps you could both a few views of your mech assembly for comparison. We should be able to figure this out. I'm also willing to let go of some of my parts if need be.

EDIT: looking at the threads on here about this same topic, I can see several pics of the earlier Z-bar type pedals. I highly doubt it would be worth the effort to modify them to make them work with the later factory style hydraulic clutch. The geometry looks way off, there's no support rods and the push rod goes thru the firewall below the steering column. The dimples the OP mentioned are curious as there was no hydraulic master cylinder until 85. My truck did have the dimples so it was easy to locate and mount the master cylinder (clutch master).

 

[squaredeal91]

I'll see about getting some pictures of some of my parts in the near future

 

[squaredeal91]

Sorry its been a few days. Heres what i dug up. The pedal by itself in my hand is the Hydraulic pedal. It appears it would fit into mechanical assembly just fine.

 

[squaredeal91]

A couple more showing placement of rod side by side marked in red