Featured Technical How likely is this to brake and I loose all braking…?

Dual reservoir didn’t quite fit mount so I had to drill out the bolt holes on the master cylinder and grind the top off some.

what’s the likelihood this will break at the bolt mounts…? And how much do I have to worry about the extra weight of this dual reservoir compared to older smaller one?

I added an angle bar to tie in one bolt hole to the cross member but am worried it’s not enough support.

 

Made images bigger for our readers
Dan

 

My first question is what the top mount is attached to and how is it attached, welding, superglue ????
If it is welded solid to the crossmember, there is no use for the angle.

My second question is, instead of enlarging the holes on the reservoir, why not use a rat tail file and make the holes in the mount wider. The material in that mount must be at least 5/16" and you could hang your whole car off of it, if you didn't mind turning your car upside down to prove a point.

My third and final question; is that an exhaust pipe flange that the reservoir attaches to. The weld I see running across it looks like it sits proud of the mating surface. If it is, it needs to be ground flat.

 

I think if you run a grade 5 or 8 bolt through and use washers on both ends (bolt head and nut) you’ll be fine. I don’t think you removed enough material to significantly reduce the strength of the flange. The real experts will be along shortly.
Dan

 

Alan responded before I posted, I a one finger pecker on my phone. Lol thanks Alan.
Dan

 

Use Grade-8 hardware.

It's fine.

 

1)
Mount is bolted to cross member.
Mount is about 1/4 thick there connected to master cylinder but thicker at the cross member’

2)
Bolt holes on car mount were bigger than master cylinder mount and slightly offset. I could have used smaller bolts but figured better to make master cylinder holes bigger…?

3 )
No exhaust and mount are far aaay, sorry m angles bad

yeah I got grade 8 bolts to upgrade from the 5 that were there before.

cool, thank you all, I’ll go with what I have. May run a flat bar under it to the frame for extra support but probably don’t need.

the exhaust pipe is annoying from a brake line standpoint and I got to bring them from the frame, up to the floor and back down because I don’t want to get to close to exhaust.

 

Additional photo of Mount.

I’ll have another photo tomorrow of the final setup I’m thinking

 

I believe the exhaust question was asking if the part of your master cylinder mount that the master cylinder actually bolts to was originally a two bolt exhaust flange and has been welded to the rest of that plate making up the bracket.

 

Should be ok, but I would have modified the mount, that way you don't need to modify any more masters in the future.

Are you trying to use the stock pedals on the F1, if so there are other ways to get a dual chamber master on there.
https://www.roadstersupply.com/Dual-Reservoir-3-Bolt-Master-Cylinder-p/rsc-55141.htm

https://nespeedshop.com/products/48-52-ford-f-series-pickup-dual-master-cylinder-adapter

 

If you are that worried, just fabricate a "U" shaped "strongback" to support the M/C flange [slip this behind]

 

I am with "1oldtimer" here, modify the bracket . Last thing you want is to have a problem with your brakes.

 

@Tim ohh ok, I get it now, yeah that might have been what my grandpa did

@1oldtimer sorry for the confusion, this isn’t the 1950 ford f1 in my profile, it’s my grandpas 1932 ford roadster. I think the brake pedal is stock but I’ll have to investigate more.

@Kerrynzl good idea, I may try to fabricate something like that.

@brading ywah I may look online for different brackets for the master cylinder.

 

Think about how much force you put into that brake pedal when that teenage "influencer" pulls out in front of you while watching a tikky-tock video.... I actually measured this, and it is multiple hundreds of pounds, depending on leg strength, ergonomics, etc.. Multiply that force by the pedal ratio and you can easily have 5,000 lbs or more generated at the master cylinder during a panic stop situation. Over 5,000 lbs that is now being reacted by chinese cast iron that has been modified and ground away.

I think the support bracket is probably a good idea too.

 

Just make a new mount that bolts to the crossmember with the proper size fastener holes and spacing.

If you ever have to replace this master cylinder - which isn't an unfathomable thing given the quality of today's products - you'll just have to go through this same rigamaroll again. Plus, a store that's paying attention may not give you a core return for that goobered master cylinder.

 

@Dennis Lacy makes a kit to convert to juice brakes with a stock pedal.

https://www.instagram.com/dennis_lacy_earlyv8garage/

 

I would not of cut the mount with square cuts , I would of made it so remaining metal was not sharp cuts but more gusset style

 

If this was me this is what I would do, starting with a new M/C. I know my drawing is not very good but I am sure you get the idea. Make a new 1/4 - 3/8 plate as per drawing. Clamp it to the old bracket. Mark the new hole spacing in the old bracket. Elongate and enlarge the mounting holes in the old bracket. Weld the new plate and new washers (go at the back of the bracket) to the old bracket. Any additional clearance needed to fit the new master cylinder do on the old bracket. you would need to extend the pedal to M/C also.

 

@1oldtimer thank you, I reached out to Dennis to see what he has.

@deathrowdave yeah I want to clean it up some but I think it’s just temporary till I get a new mount.


I found this and may get it but I don’t like that it doesn’t have the angled extra support in the back like my current one has : https://www.millworkshotrod.com/products/1932-master-cylinder-adapter?variant=44461398753518

@brading i thought about that but if i was to enlarge the original bracket holes the original bracket would almost be almost cut in half. Just 1/4 an inch of the original bracket would still be connected. I’ll probably keep the original bracket uncut because it fits 1960-ish single reservoir master cylinders, which my grandpa originally had.

@Kerrynzl got me thinking of something. Till I find a new bracket I’m going to try and see if I can cut a metal exhaust flange in use it like he sketched in the photo.

plus debating if o want to add brake booster so that would be a different mount too.

Often times I get “analysis paralysis” and I got to remember this is not a forever solution, just a safe solution while I drive around the block once a week till I find a new bracket I like. I’m painting my 1950 ford f1 and got to focus back on that, plus got to redo its brakes and swap transmissions on it…

 

Sdsurfer01 I can see what you are saying but if you welded the new piece to the old bracket it would be stronger that it was IMHO.

 

Good to know it will be stronger, I’m always unclear on material stress and strength.

Unfortunately I don’t have a welder right now. My buddy had one and used to help with stuff like that but he moved out of state and I haven’t bought my own yet.

Probably cheaper to buy a new bracket, which I probably will end up doing in the future.

 

If you got the Millworkshotrod bracket and would like more make it stronger I would thought that you could find a company near you to weld a strip up each side to make it like a channel section.

 

Only concern I have is the mounting bracket. Since it's only bolted with two bolts at the top when you're pushing on the brake pedal it's going to be putting a lot of pressure trying to push the master cylinder and bracket away from the frame it's bolted to. That's a lot of leverage to only be bolted higher up above the master cylinder.
I'd want the bracket welded or bolted more securely at the bottom myself. Wont take much to either weld it to the frame below, or add a plate to the bracket that can bolt up through the frame at the bottom of that bracket. Then it wont twist and try to pry away when the pedal is depressed.

 

Looks like there are 5 bolts thru the bracket and if the existing welding is good, the addition of a pair of triangular gussets on the sides would improve it. Remove and take it to trustworthy welder.
But; since it is already made of multiple pieces; I would just make a new bracket in the same shape out of 3/8" plate using the same bolt holes. 3/8" flat would suffice with no need for braces, gussets, or welder.

 

Thanks all for the help and suggestions.

i ended up getting a new master cylinder cuz after further research my front wheel cylinders were 1 1/4 bore and the master cylinder I was going to put in was 1 inch bore. Previous one was also 1 inch bore and I think that was why it was almost to the floor for brakes to engage. New master cylinder is 1.125 bore so from reading it will be harder to press but shorter to engage from my old MC.

the new master cylinder has 7/16 bolt holes where my old bolts were 1/2. I had to still do some grinding but not much and I used 7/16 grade 8 bolts to mount.

I took a 2.25 inch exhaust flange and cut off the top and looped it under like @Kerrynzl had suggested.

I’ll bleed brakes tomorrow and see how it works.

When I changed the rubber front brake lines last year the date on them was in 82 so I imagine that’s when my grandpa had the mount made.

@brading good idea, there is a local rod shop that works almost exclusively on 32s. I’ll give them a call and probably swing my and see if they can make me a mount like the millworks one but thicker and I like @RICH B suggestions on the triangle extra support.

I’ll probably move back to painting my 1950 ford f1 while I wait for the shop to make me a new mount and swap the mounts when I’m done with my truck. I’ll probably also have the shop make the mount where I can mount either just a master cylinder or also a brake booster. It’s a 39-48 flathead so I got to do some research on if I can even put a brake booster on.

plus I also got another forum post about the ebrake throw. I want to get that squared away before I drive though as an extra precaution.

below is a photo of the finished for now job. It’s not pretty but hopefully safer than before. Angle bar connects to crossmember and flatbar under MC connects angle bar to frame.

 

And that's the breaks

 

A heads up and hopefully not a jinxing, with the change to 1.125 master you could well find it impossible to generate enough line pressure, no matter how hard you stomp, to be able to achieve strong, emergency stop kind of braking. Slowing down will be fine, but when you really need to stop....
But it also depends on the wheel cylinder sizes, so it's possible the combination might be OK.

Chris

 

@Happydaze previous master cylinder was 1 inch and I got firm peddle about 2 inches from floor.

looks like I have stock peddle and front wheel cylinders are the 30s/40s juice brakes with 1.25x1 bore. Rear brakes I updated to bendix style brakes with 1 inch bore.

my understanding from other hamb threads is the larger bore will have less travel but require more foot force for stopping power?

 

Measured and pedal ratio is 4:1. Still investigating if the 1 1/8 will work or I got to start all over again.

Also I checked and my push road throw is 1 inch