Brake pedal travel with Wilwood dual master

[plateaucal]

Get good documentation of their assessement...in writing, countersigned, with receipts. You may need it... The folks doing disc brake conversions are fine, as long as they never drive an official road.

[faux40]

Take the is a grain of salt considering that this from someone who, 1) is totally committed to a disk conversion, and 2) had a stock drum-brake patrol wrecked due to a total brake failure!

Have all four drums been properly adjusted? I haven't seen that topic in this thread (or, am I blind?). I'd venture to guess that what feels like freeplay may be just getting all the brake shoes up to their touch points on the drums before the system can start really building pressure. I would expect the pedal to feel soft until all 8 shoes are touching drums.

My concern is that the getting the shoes to the drum will consume more fluid than the master cylinder should supply for that part of braking, leaving less reserve for braking (as in not enough remaining fluid/piston travel to build max pressure). Unless you run out of pedal travel before running out of MC piston travel (MC should bottom just before the pedal), the pedal linkage slack doesn't matter from a hydraulic perspective (not saying that it doesn't matter for safety and operation though... just not hydraulically)

My 2 cents on the Wilwood master -- With drums and pedal linkage all properly adjusted, as long as the Wilwood master cylinder has the same piston diameter and stroke, there should be zero difference between that and the stock master cylinder from a hydraulic perspective. Properly fitted and adjusted, you shouldn't be able to tell the difference in the two MCs from the cab.

Anyway, that's my two cents, and worth every penny!

J

[RiverPatrol]

I'm really disappointed in you two. This is me we're talking about. Do a search of the forum, please count how many times I have insisted and reiterated to someone that brake adjustment is critical to a solid brake pedal and a well functioning brake system? Sheesh. I oversaw them do the brake adjustment. I visually inspected the brakes themselves. The pedal is solid and positive, it just visually seemed to have more freeplay/travel than what I expected. Now that I have it here I test it myself and the pedal definitely stops a good 1 ½" - 2" from the floor, it is solid, not mushy on the first try.

[RiverPatrol]

Ok, doing a little further research on this just out of curiosity. I'm satisfied with the pedal travel although I might try and get a bit more adjustment out of the push rod. But, while reading the documentation I discovered something interesting. This model of Wilwood master cylinder is specifically designed for drum brake systems and as such it does not require the use of a separate proportioning valve. So, this just tells me that there are different conversations to be had regarding dual masters depending on whether it involves a disc brake conversion or keeping the original drum brakes. I think this is important information to know!

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[Oddbod]

River, I am no expert and dont even own a Patrol as you know.
However being anb hot rodder and more recently upgrading my brakes at home on my 1959 F100, I got caught up with the pedal ratio.

My pedal ratio was designed by Ford to activate 4 wheel drum brakes (1 1/8" bore) with no power booster.
I added 1990's Dakota front discs, to 1960's Ford Galaxy rear drums all via a 1970's Camaro master cylinder and booster (1" bore).
I never did change the pedal ratio which would probably have solved most of my pedal travel issues, but looking back now, most of the issue was getting use to the new feel.

I can not lock my wheels up easily, which I see as a good thing especially in the wet, but have locked the fronts up on dry black top during an emergency situation.
After that event I felt I knew my brakes better and felt way more confident with my F100's braking ability although it was much different to the old pickups brakes and not like any of my modern cars.

I also added a proportioning valve in addition to what came with the Camaro master cylinder as I found my rear brakes at first test drive really wanted to lock up and were doing way too much of the braking in general.

There are several things to consider when doing a brake swap/upgrade and these are;
1. Compatible pedal ratio.
2. Correct master cylinder bore which can be related to No 1.
3. Free play between plunger rod and booster which has been discussed.
4. Adjusting to the new feel and travel of your upgraded brakes.
5. Compatibilty between new front discs and old rear drum with wheel cylinders...

Sorry that I can not be more subject specific for your vehicle, but I am hoping my comments may provide fertile ground for new questions or get your attention in some other way that may help you.

I did originally purchase an after market master cylinder and booster from a place in CA and like many other suckers, I mean purchasers threw it in the trash as it was terrible and would not stop my pickup safely even at slow speeds.
That specific afternmarket setup was dangerous and junk and I read regularly on Forums about many dissatified folks similar to me out there who are reporting their bad experiences, so never just accept that what is on offer is any good...

[RiverPatrol]

Thank you Oddbod, these are all good things to consider.