JR_Charger
Well-Known Member
The gasket will not sit flush against the Dr Diff mounting adapter. The gasket is for a drum car. What do I need to do here?
Plastic Firewall Gasket and Dr Diff 15/16 Master Cylinder
- Thread starter JR_Charger
- Start date
Looks like you need to enlarge the hole in the firewall and gasket. Edit:In the picture the studs go threw the firewall into the interior? On the threaded side of the plate that raised area does that go in the firewall.
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gkent
Well-Known Member
Ditch the gasket for a foam one. Less likely to leak also!
Just use a foam gasket.
If you purchase meat at the store, save the package tray and make one (wash it first).
Mike
Mike
JR_Charger
Well-Known Member
I sure hope I don't have to change the hole in the firewall. I know there are people here who have the DoctorDiff 15/16 master cylinder. I haven't seen any install issues in their threads. Strange.
Anyway, the rubber boot over the brake pedal push rod fastens on to the plastic gasket, so the gasket should be kept, but there's nothing wrong with putting another gasket in there. I'd need to put some spacers on the studs so the MC doesn't rock. I'm very slight concerned about pedal travel issues, but it probably won't be a problem.
Anyway, the rubber boot over the brake pedal push rod fastens on to the plastic gasket, so the gasket should be kept, but there's nothing wrong with putting another gasket in there. I'd need to put some spacers on the studs so the MC doesn't rock. I'm very slight concerned about pedal travel issues, but it probably won't be a problem.
gkent
Well-Known Member
The hole in the firewall should already be big enough to accommodate a p/b unit so I don't think that will be an issue. Also, all those Mopar/Strange masters are the same casting regardless of bore size. So if a 15/16 fits, so will that one. The rubber boot should go on the master BEFORE the black adapter - there should be a relief in either the adapter or the master to sandwich the rubber boot. Toss that plastic thing in the trash - the rust stains indicate it leaks anyway !!
wahya
Well-Known Member
Question. I just finished putting in new brake lines, shoes, and master cylinder. I’m now working on the brake pedal and maybe I’m just getting old, but the pedal seems to be sitting high and it’s uncomfortable to reach. I measured the brake pad height from the padded floor and it’s about 7 inches, which seems to be in line with some of the posts about it.
It’s been a dozen years or so since I put on remanufactured MC and as I recall, there was a plastic gasket that looked liked the one pictured on this thread that I removed. The gasket was brittle and it broke when handled. The new MC came with a foam gasket which has pretty much been used up. This new MC didn’t come with a gasket. It’s hard to tell from the photo, but the gasket shown could be 1/8” ?.
I have a little play in the pushrod and I can lift the pedal about an inch, which translates to movement at the pushrod of maybe 3/16”- 1/4”. I’m trying to figure out if a 1/8” gasket on MC would get me any height reduction on the brake pedal.
It’s been a dozen years or so since I put on remanufactured MC and as I recall, there was a plastic gasket that looked liked the one pictured on this thread that I removed. The gasket was brittle and it broke when handled. The new MC came with a foam gasket which has pretty much been used up. This new MC didn’t come with a gasket. It’s hard to tell from the photo, but the gasket shown could be 1/8” ?.
I have a little play in the pushrod and I can lift the pedal about an inch, which translates to movement at the pushrod of maybe 3/16”- 1/4”. I’m trying to figure out if a 1/8” gasket on MC would get me any height reduction on the brake pedal.
gkent
Well-Known Member
Pedal height is determined by the "stop" on the pedal frame. There is a rubber "damper" there and if that is missing it will result in the pedal coming up higher (and potentially pulling the pushrod out of the m/c).
wahya
Well-Known Member
I just looked again and all there is, is a brake light switch that is about halfway repressed with the pushrod resting on it. I can push the switch in more without the pushrod moving. The switch is attached to a bracket that appears to be adjustable. No places for any rubber stop to attach to that I can see.
To OP, if you decide to pitch that what appears to be plastic or hard neoprene material gasket, you can pitch it my way.
To OP, if you decide to pitch that what appears to be plastic or hard neoprene material gasket, you can pitch it my way.
JR_Charger
Well-Known Member
I'm sure I've seen new ones available. It's not at Detroit Muscle Technology ATM. Maybe someone else will know who has them?
JR_Charger
Well-Known Member
The rubber boot fits inside the adaptor, but it's not snug. It fit over a plug on the plastic gasket, and held tight to that.
wahya
Well-Known Member
I did look at some online. I selected one, put it in my cart for $3.99. Total with shipping and tax came to about $25. Could have put it in an envelope with a stamp.
So next plan. Went to my neighbor who is always working on stuff. He had a small piece of Lexan left over in his garage. One eighth of an inch thick and it does not compress. I used my old master cylinder as a template and made a new gasket that works like a spacer and slipped it behind the mc.
I'm pretty happy with the result. The brake pedal height was 7”, it's now 6 3/8”. So the 1/8 space turned into a 5/8" difference.
The brake light switch only stops the brake lever after it goes all the way in. It does not activate lights at rest now, but only touching the pedal does. I may need to adjust the switch mount some.
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JR_Charger
Well-Known Member
What year? That doesn't sound like the way mine works. The switch is at the top of the pedal's travel and activates when the pedal is depressed.
wahya
Well-Known Member
It’s a 71. It works the same as yours. What I am saying is that before I put the 1/8” gasket in, the lights activated partway into the stroke of the pushrod, maybe a third of the way in (just guessing here, the difference is just 1/8”). Now, without touching the pedal, the lights are not activated, which is correct, but the lights come on at the very first part of the stroke. Not sure that is a bad thing, but I may adjust the switch just a tad.
Also, I’ve been reading about pushrod stops, and somewhere I read about a spring attached. My car has none of that. The pushrod is secured in the master cylinder and the mc determines the stopping point of the brake pedal (at rest).
Also, I’ve been reading about pushrod stops, and somewhere I read about a spring attached. My car has none of that. The pushrod is secured in the master cylinder and the mc determines the stopping point of the brake pedal (at rest).
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