Converting to electronic brake booster

[fredc]

So I have a question for any knowledgeable souls out there. I have a 77 Bronco with a mid 90's Mustang 5.0 and a mustang hydro boost brake set up. I am wanting to convert to a Tesla electronic brake system using a bosch ibooster. So the question I have is about switching out the Master Cylinder. The one that comes with the ibooster has a 1 inch bore. I have disc front and rear and need a 1 1/8 inch bore Master Cylinder. I have a Welwood MC with a 1 1/8 inch bore. the mounting holes on the MC are oval so it will bolt up to the ibooster brake booster just fine. It just needs to be clocked about 45 degrees for the new MC to be level. The only other issue is that I need to fab a push pin for the booster push rod to make conatct with and be flush with the new Master Cylinder plunger. Does anyone see any flaws in the idea? I should be able to switch out the Master cylinder? Correct. All the Electric vehicle forums do not talk about switching out the MC.
Comments and feedback welcome.

As part of this I am also switching to a Volvo Electric Power Steering pump. But that is very straight forward.

thanks Fred C

 

[DirtDonk]

That should be interesting.
First time I’ve heard of someone doing that at least here on the forums.
Personally, I would stick with the 1 inch master initially. Or is that going to take some tubing adapting as well?
I guess part of it depends on which disc brakes you have front and rear. The standard front discs on a 77 used a 1 inch bore master cylinder so if that’s what you’re using up front your smaller master should not cause a problem.
Do you know what’s on the back?

 

[fredc]

you do need an adapter from metric to 3/16. Easy enough and I have them already. So it was a disc conversion front and rear.
Front GM 2 15/16 bore
Delco 5473499
Rear 2” bore
Caddy rears

My Bronco had drum brakes front rear so I had to do the conversion.
So you think staying with the 1" bore MC that came with it should work? Wilwood tech support told me to go with the 1 1/8 bore.

 

[DirtDonk]

So I guess the previous owner got rid of the original discs to swap them onto another bronco perhaps.
Or just wanted the larger pistons, or just liked GM brakes better.
Whatever, the larger master bore is not out of line for these larger piston calipers. On my own vehicle however I wouldn’t hesitate a moment to at least try an 1” bore master.
If that’s what you’re running now and you have a firm pedal then I see no reason to switch it out unless you’re trying to get less boost.

Which master are you currently running?

 

[fredc]

I just bout a Welwood MC for this. And like I said, it has a 1 1/8 inch bore. So try the setup with the MC that comes with the Tesla brake booster and see how the pedal feels. As long as I don't go all the way down to the floor with my pedal I should be good. Again thanks for the feedback.

 

[36Fan]

Any updates on this? I'm ready to dive in and try this on one of my trucks.

 

[fredc]

So I was able to use this MC from Jegs https://www.jegs.com/i/JEGS/555/631...FgcPI8Mbvdu-p0B4lkA_WPzjl-mRGJIRoCLMIQAvD_BwE with this adapter plate I got on ebay https://www.ebay.com/itm/2755817189...d=link&campid=5335857059&toolid=20001&mkevt=1

I had to rotate the plate slightly and drill 2 holes so I could bolt it to the booster. I can post a pic. I had to get a metric bolt I think it was an M8 or M6 and about 3 inches long. to make a new Booster pluinger going into the MC. I used this tool for the depth https://www.amazon.com/dp/B0BDDBNDBX/?tag=classicbroncos-20

 

[36Fan]

Are you still fitting everything up or have you driven it yet? Curious as to how much your Bronco weighs?

 

[nvrstuk]

I feel the 1 1/8" is the min dia for those JD6 calipers. Keep us posted on how it all goes. I have been looking at doing this but I have toooooo much going on right now so thanks for posting up!

 

[Dylan_Shaffer]

I’m also in the process swapping to a Tesla brake booster, looking forward to seeing how it turns out!

 

[nvrstuk]

I feel the 1 1/8" is the min dia for those JD6 calipers. Keep us posted on how it all goes. I have been looking at doing this but I have toooooo much going on right now so thanks for posting up!

I’m also in the process swapping to a Tesla brake booster, looking forward to seeing how it turns out!

I'm going electric strg on a street build I'm working on. Less hoses, no pwr strg pump and cleaner install.

 

[fredc]

I am also swapping in a Volvo electronic power steering pump. So electric brake booster, electric fan and electric power steering. Lots of juice so I also had to find a high current alternator. The fan is out of a ford Taurus and seems to use the most amps.
I spoke to Wilwood Techs about their Master cylinder. Gave them the bore size of my rear and front disc brakes and they came back with 1 1/8 bore for the MC. I can't remember why I did not go Wilwood for the MC but Jegs instead. Just finishing up on the wiring and hope to fire it up in the next week or two

 

[nvrstuk]

Are you still planning on the Tauras/Volvo fan?

 

[fredc]

The fan is in and pulls a lot of air. Its a 2 speed and I am using the Volvo 2 speed relay module. So far the fan works great

 

[nvrstuk]

The Tauras /Volvo fan does work great.

There are new OE fans out that draw about 40% of the amperage of the Tauras. I think Derale is getting on board too.

I was thinking of this for you because of the electrical draw that you will have and if possible why not cut it in half?

 

[fredc]

You are right about that. I am pulling a lot of amps. Will have to look into another fan option. thx

 

[nvrstuk]

Late camaro amd Mercedes seem to have a good dia for a stock EB rad dimensions and they are PCM so they draw about 1/2 the amps.

Couple guys I know with large strokers in EB's use them.

Keep us posted

 

[fredc]

Thanks and will have to look into that

 

[36Fan]

The fan is in and pulls a lot of air. Its a 2 speed and I am using the Volvo 2 speed relay module. So far the fan works great

I run this set up on my desert truck. The initial start has a big spike in amp draw but comes done quickly and rarely see the high speed turn on.

 

[nvrstuk]

I run this set up on my desert truck. The initial start has a big spike in amp draw but comes done quickly and rarely see the high speed turn on.

Gotta ask on your race truck. Are you doing much extended low speed stuff?

Reason I ask is with my big radiator on my Torture cooling test that I posted up here yrs ago that compared the Exploder to the Tauras fan, the Tauras when going slow would never kick off high and therefore was drawing high amperage the entire time.

I would think the difference btw moving at speed- even under load forces a lot of air through the radiator compared to those in city traffic or in my case rock crawling or slow speed trail stuff.