TECH 101 86 down, 87-91, 92 up Std pedal assemblies!!

Hey folks

Just a bunch of pics here to portray some significant differences from years to years style to style.

I've got an 86 down pedal assembly

I've got an 87-91 pedal assembly

I've got a 92 up pedal assembly THIS ONE IS from a 94

They are clearly marked and you'll see the differences.

These are ALL vacuum brake, hydraulic clutch setups.

So ALL 3 together from a variety of angles and perspectives.













For these next three you will see I've pointed to the CLUTCH actuation arm with the proverbial problematic pin that wears out. In one case it's been poorly replaced by a bolt. Notice the differences in the ARMS that's my point here!




If you looked close you will see the 97-91 and 92 up use what appear to be the same arm. If I have time I'll locate my 87-91 spare arm and do a direct comparison to the 92 up.

So Now on to the next post for a few more pics

Thanks for looking

Al

Hey back again,

So now let us look at these a little closer as individual model year assemblies shall we...

Starting with 86 down





Here we have 87-91




Lastly 92 up




These show differences everyone can understand.

If you have questions I'm happy to answer or take other angles or shots.

Al

You know this is very good info for someone that wants to maybe upgrade to a "newer" style pedal assembly or repair one.
The pics are nice for getting a idea how stuff comes apart, before a person would tear into something.
I see a "ultimate guide for part cross reference" on the OB hosted by Al.

Awesome pictorial! Definitely tech worthy!

Always nice to look over what Al takes great pics of. I think he missed his calling in life... Its always enjoyable to actually SEE something clearly when a pic comes on this board. Sometimes I look at a blurry pic and wonder... Whos trying to hide a face or what..

The brake peddle in the 87-91 will fit in the 92 assembly, I pulled the hydro peddle out of a 88 and put it in my 94. Just FYI

IIRC, you can interchange the petal assembly between 87-91 and 83-86 units. I know I have some combo of earlier and later parts but I can't for the life of me recall exactly what I stuck under there.

Well folks looks like there is some theoretical interchange. Looks like I need to clearly mark the parts/pedals and spend an hour or two playing with them interchanging one another or doing direct comparisons side by side.

I'll keep this in mind especially for those doing OBS hydroboost swaps. Or 86 down hydroboost swaps. This may be the mother of all info sessions for those folks!

I've got to redrill a pedal pin location for my OBS cab so I'll keep it in this thread.

Al

What I found funny was i have a 94 auto brake peddle and a 95 manual brake peddle. If you look at the side of the brake peddle the part # were identical (and we all know the peddles are different) guessing the arm part of the welded assemble is the same before they weld them to the pivot and the foot pad?

can-can, nananana can-can na na na can-can nanana can-can.

Yes, that is exactly what those pedals on their backs reminded me of.

I shall now go find 16 beautiful ladies with feathers up their ***** and can-can off into the sunset.

riotwarrior said:

... Or 86 down hydroboost swaps. This may be the mother of all info sessions for those folks!
...
Al

Click to expand...

If you are trying to decide which to look at first, I'd be real interested in knowing if the 92+ fits on the 86 cross pin and how close the pin on the brake pedal lines up to the center of the master cylinder mount on the 86 bracket. Everyone said, use the late model pedal but I think they were putting it into an OBS truck.

dgr said:

If you are trying to decide which to look at first, I'd be real interested in knowing if the 92+ fits on the 86 cross pin and how close the pin on the brake pedal lines up to the center of the master cylinder mount on the 86 bracket. Everyone said, use the late model pedal but I think they were putting it into an OBS truck.

Click to expand...

We have a bidder! How about I take one of my already apart 87-91 and do some comparisons that way. I'll see what I come up with shortly.

been super busy with Rodeo, dance and parade...ugh...I'll see bout this cause that 92 setup will get redrilled for HB ASAP!

Hi everyone,

I felt today was a great day to do some checking of some hardware I have floating around

ONCE AND FOR ALL dispelling myths and conjecture

Well for those that seek knowledge of brake pedals please look here!

I have for you today layed out my assemblies, (granted all for standard trans/vacuum brake) and I also grabbed my single stand alone 87-91 Std trans vacuum brake pedal for this as well.

For comparison I wanted to see if the brake pedals where the same or not. I labeled what I could as in the first set of images in this thread.

You will see by measurements and comparing the 87-91 pedal to the 86 down and 92 up that there is indeed little if any difference other than manufacturers variances.

I've done my best to measure in the same way on all the pedal assemblies but clearances made it just off a bit. Take this into account as I feel very confident they are the ONE and the SAME throughout the years. I know for me I'd use any year on any pedal assembly.

What I'm getting at is for those wishing to do a Hydroboost just grab the damn thing off any year with pedal lines and PS reservoir and swap your vacuum pedal out and the hydro in! It won't matter if it's an 97 pedal in an 84 or 94 they are for all intents and purposes the same setups just different mount brackets!

So here are todays pics for you to understand visually what I'm saying!

Here they are all layed out with the single 87-91 vacuum brake pedal in the foreground


stand alone pedal




86 down setup


This shot shows the 86 down assembly with the 87-91 pedal resting under the 86 pedal to show similarities, believe me when I say they are practically the same pedal


Here is the 92 up setup, I have two one with the nut for more surface area for bushing and one without both are the same pedal




And again I've layed the 87 pedal onto the assembly for comparison purposes



There is absolutely no doubt in my mind that we can fully interchange our pedals from STD pedal to STD pedal, I cannot confirm that with auto's however I suspect it would be similar.

I hope that this helps everyone in their quest for a pedal for hydroboost.

There will be one more update to this with the creation of my HYDROBOOST pedal from the lone 87-91 and retrofitted into my 92 up pedal assembly.

Thanks for reading

Al

Good info since i'm planning on converting from C6 to ZF5.

It seems like there would be a market for someone with the skills to convert vacuum pedals to hydroboost pedals. Now that the pedals seem to be the same for all years. Al, is the shaft diameter the same on them all? I guess liability would be a big problem with a program like this.