The Stovebolt Site Forums The Shop Area The HiPo Shop Power brakes AND manual transmission?

I've touched on this in another thread, but I'm looking for feedback from EVERYONE.
Every power brake kit I've seen for sale that mounts on the same holes as the original M/C says they won't fit manual transmissions.
Is this because of the clutch linkage?
Is it close enough to perhaps modify the linkage to work?
Is it a lost cause?

What rule says you have to mount the power unit in the same place as the old manual one? Many of the ones we mount are anywhere from a foot behind the factory mounts to just in front of the rear end. This means all that has to go through the clutch/brake/ shift linkage is a small rod. On ones with a long distance between pedal pivot and booster plunger we use a bell crank so the long section of the rod is PULLING and the short pusher rod runs between bell crank and booster. There is also a "remote mount power brake unit" where the booster unit can be ANYWHERE, even in the glove box if that's your wish. The factory master cylinder has a line to a slave cylinder on the booster which works just like a hydraulic clutch set up. If you don't want to crawl under the truck to fill the MC then use a remote firewall mounted reservoir. Don't search for hens teeth---be creative.

No rule... just making note of what's available and SUPPOSEDLY the easiest to install. But only if you have an automatic transmission, apparently.

You will have to make modifications but many have done it. It's kind of silly to offer a "kit" made of a booster and MC that any one can buy at a FLAPS and bolt them together and then say it won't fit manual transmissions. How many automatic trucks were sold in 49? Maybe none?
Anyway you will have to do what everyone else does, get the parts and figure out how to mount with what you have under there.
OR...........put in an automatic (that should come with the "kit")

Also beware of kits for manual MCs that mount where the factory one mounts- The one I bought from Jamco came with a bracket that placed the MC and proportioning valve squarely in the middle of the crossmember at the rear of the trans. My friend with the welder and the skills had to fab up a bracket to allow everything to fit. Without that bracket, the rest of the kit is stuff found at the FLAPS, as noted, so what's the point..? That was quite frustrating.

I know, it's a little off topic, but slightly relevant.

Excuse my ignorance, but what is FLAPS?

Friendly Local Auto Parts Store

What about an hydraulic throwout bearing and eliminate the clutch fork.

Hens teeth found- Look at the POL kit (Performance Online). I used this one in my '50 3600 with the stock crossmember and a Manual T5 transmission. Everything fit just right and works great.

M/C kit that works with stock clutch

or, for all drum brakes:

Drum brake MC kit

My truck: M/C kit installed wtih stock clutch

Never crossed my mind.... I like the idea! May just have to look into that....

Did you happen to find a 8 lug disc brake kit?

Dave,
That's the exact kit Jamco sells (same photo on their site). The crossmember I had interference with is the one at the back of the stock 3 speed trans, which is not present in the photo of yours installed. Just sharing for anyone following along.

I converted to five lug axles. I wasn’t interested in the stock rear end ratios I could choose from, or the rear brake parts supply/cost issues. It wasn’ti an easy choice to remove the stock rear end, but I plan on driving the truck regularly and keeping it for a long time, so I went with a GM 8.5” rear end with 3.73 gearing. I converted to a 3100 front axle and then 5 lug disc from there..


As far as the crossmember goes, my crossmember is stock and I have not removed or modified any crossmembers. My understanding is that the 3100 and 3600 frames are identical from the front up until under the rear of the cab, where things begin to change... not sure why this kit didn’t fit your truck...?

It's not that it didn't fit, I haven't tried yet. My concerns came from the disclaimers of the ones I had seen for sale so far.
If it works for you, I have no reason to believe it wouldn't work for me.
What are the 8.5" rear axles found in? Are they difficult to source?

And do the 8.5's bolt directly in?

Mine's a 3100- maybe that crossmember is different between 3100 and 3600..? The Jamco bracket (without the added length of the booster) placed the end of the MC and prop valve in the same space as the crossmember at the tail end of my trans, not present in your photo.

I see the OP has a 3600, so maybe my chiming in on this thread is completely irrelevant since I have a 3100 and am not running power brakes, though maybe someone with a 3100 will find it useful (maybe not ).

There is no “bolt in” rear end for the 3600. For any donor axle, You’ll have to set the driveline angle, remove and replace the leaf spring perches, new shock mounts on the axle, and have a driveshaft made.

I used a GM metric rear end- mid 80’s ZR-2 S-10 Blazer because the width was correct.

Dave: does this meet his criteria of "mounts in the same holes as orig"? With no mods or parts to make? If so, what mods? Very nice work by the way!

Tadd: I would not get into finding a hydraulic clutch bell housing and all that. Possible can of worms regarding fit to motor, trans mount, pedal linkage. Just get a kit like Dave and others have done. I am thinking of the stock hydraulic clutch from 60-66 which is on the passenger side. Others may be thinking a hydraulic conversion using your bell housing with fork on drivers side.

bartamos,

I fully expected the kit not too fit after looking everywhere for one that would allow me to use my stock clutch pedal, but everything did fit. It used the same mounting holes for the bracket, and the stock pedal shaft. The booster fits without hitting anything and the adjustable pushrod provided was the right length for the stock brake pedal.The M/C has enough room to remove the cover to fill it, however, the servicing hole in the cab floor will no longer be in the right place (the booster moves the M/C after quite a ways), so you either have to get the remote reservoir kit (I did not), or use a mirror and a squeeze bottle to fill it from under the truck, which works fine for me.

You will need to modify the brake lines to connect to the new M/C location, which is at least another 8 inches or more aft of the original location. I do not believe that there are any RPV's in the drum brake M/C, so if you want them, you'll probably have to add them in the circuits. I have 4 wheel disc, so I used 2lb RPV's front and rear. I used the disc brakes that came on the ZR-2 rear axle, and the CPP disc brake kit up front. The brakes feel great. Performance Online has pretty good tech department and was pretty knowledgable about their product.

One more thing- be sure to buy the dummy plug for the proportioning valve, so that you can bleed the system properly.

Good info. Thank you.

What is the full name of CPP? (Sounds like a vendor name that I'm not familiar with.)
RPV...Rear Proportioning Valve?
Did the kit relocate the M/C back far enough that an access hole could be created under the seat?

RPV= residual pressure valve. This valve exists in most original drum brake master cylinders, but it now often missing from FLAPS replacement master cylinders.
CPP= Classic Performance Products
Relocation of MC= Yes, the MC has to sit BEHIND the booster, so it will now be pushed towards the back of the truck and the MC servicing hole in the truck floor will no longer be positioned over the top of the MC.

I'm installing a Dual Master cylinder that has a valve (attached) to control the flow of brake fluid. Y'all mentioned using a plug to assist in bleeding. Why/How is this done?

I'm a old Electrician. Trying to be a Mechanic.

The valve underneath is the proportioning valve. IF it has a brake circuit warning switch installed (I think that some don't), the switch must be unscrewed and a dummy plug installed while brake bleeding, because the warning switch is activated by a differential in front/rear brake pressures- it does this by having a sliding piston setup in the valve that gets pushed one way or the other when brake pressure varies between the front and the rear systems. The piston has a notch in it where the tip of the switch engages .... If you are bleeding the system without a dummy plug, the warning circuit piston will move out of position and not return to neutral, causing the brake warning light to remain "ON" all the time (although our old trucks are not wired for brake warning lights).

Gracious, Mine is made by Ellwood. I'll see what there web sight says. Otherwise Thank You Dave. I've spent an enormous amount of time working on little British Cars. Never bled a master cylinder before.

Mine also has a brake switch in the Proportion Valve

I have a kit installed with a t-5 tranny. But I do think it was installed before I made the change to the t-5.

Which kit?
I'll be using a T5.