Electric vacuum pump to improve brakes

[macleanflood]

So how does one measure the bore? I assume remove the master...then what...pull the piston out?

I can only see one part number for the master cylinder in Rock Auto.

Google searches didn't come up with anything.

-Mac

 

[mrblaine]

So how does one measure the bore? I assume remove the master...then what...pull the piston out?

For a normal master, yes. There is a vacuum seal and a snap ring at the back of the TJ master.

I can only see one part number for the master cylinder in Rock Auto.

Google searches didn't come up with anything.

-Mac

Info is surprisingly sparse. If you click on the info box on most other offerings on RA, it gives pertinent details.

 

[macleanflood]

I'm going with 1"

-Mac

 

[Weasellee]

Just read through this thread. Cool shit Mac. Let’s get it properly bled and tested! Could be a game changer for some.

 

[macleanflood]

Waiting on more bleeding until my Canadian reservoir arrives. It shipped but who knows when it'll get here

Meanwhile I worked on finalizing some wiring.

Put a temporary switch in the passenger footwell. Waiting to take the center console apart until my custom Carling switch arrives.

One trigger of the relay will be the cigarette light... basically ignition on...and the second will be the "bypass" switch on the dash that I will engage when crawling.

Went for an hour ride on Forest Service roads. 4 low through two big washouts. Found a wrecked Mazda Tribute down an embankment and got asbestos testing done on an abandoned trailer...all things Friends of Fall Creek Watershed...a non-profit we formed to clean up our public lands...works on... volunteer cleanups every Sunday.

The brakes really grab quickly. I had to pull the rod down slightly to engage the pedal button. Thinking I might move the button up an inch to increase the throw...right now you have all the brakes inside of 2 inches of pedal movement.

Best way to describe it is vacuum assisted brakes are on a logarithmic curve...comes on slow and ramps up the more you mash the pedal.

IBooster is very linear. You get used to it...but it's almost scary at first.

Going to look into if I can engage the CAN bus programming. Apparently there are different "modes" you can set. And I'd love a electronic brake for winching.

-Mac

 

[mrblaine]

The brakes really grab quickly. I had to pull the rod down slightly to engage the pedal button. Thinking I might move the button up an inch to increase the throw...right now you have all the brakes inside of 2 inches of pedal movement.

That is how hydroosted brakes are when the master cylinder is too large. Be cautious with the brake pedal arm, they are very hard and difficult to drill, they are either case hardened or through hardened. I suspect case hardened. That means if you weld on it, the potential for failure goes up significantly.

The reason you had to pull the push rod down is due to the fact that the factory booster has an angled mounting face that points the booster push road at the correct spot on the pedal. I've built many adapters for vacuum and hydroost set-ups into the TJ and never have built a simple spacer, they've always been angled.

Best way to describe it is vacuum assisted brakes are on a logarithmic curve...comes on slow and ramps up the more you mash the pedal.

IBooster is very linear. You get used to it...but it's almost scary at first.

Our Transit Connect is like that. I don't drive it very much but I do move it around from time to time and the first pedal push always slams the brakes on. But, it only takes one stop to get used to it and then it is all better. I had to look it up to see if it had an e-booster, it doesn't, still vacuum.

Going to look into if I can engage the CAN bus programming. Apparently there are different "modes" you can set. And I'd love a electronic brake for winching.

-Mac

Good luck

 

[macleanflood]

This guy has an iBooster working on an RC controller...


View: https://youtu.be/DybJ7xEdUFo?si=tDELcTveHRnWYQ6Q

-Mac

 

[macleanflood]

Brat industries reservoir installed. Nice quality machine work. Only downside is you need to hold the black aluminum reservoirs as you unscrew them because you have enough leverage to unscrew them from the manifold. It really needs a set screw or pin.

Re-bled the master and got lots of bubbles out. Then opened up the bleeder and worked air out of the lines... didn't see much.

Waiting for my switch to arrive and then I'm going to rework some of my wiring. Trying to locate a terminal to add a maxi fuse to my PDC for the yellow wire.

-Mac

 

[macleanflood]

Ok... finished reworking some of the electrical.

Pulled the yellow 12g out of my relay and fused it with a 20a fuse straight to the battery.

Blue wire runs to my relay box. Dual triggers on the relay...one side gets power from the cigarette lighter which is switched power. Other side goes to my CH4x4 custom printed iBooster switch. Fused with a 5a fuse.

The switch is partially unnecessary. Since the iBooster gets constant power it can decide when to switch on and off. It seems to have a default timeout of a minute or two after the blue wire looses power. I'm wondering if that timeout valve is settable using CAN.

Nonetheless the switch bypasses the brain and leaves the brakes on all the time. I'll use the switch when crawling.

Also good news...Corsa Technic seems to have located the Maxi fuse terminals for the PDC. They're Ford style... Chrysler didn't bother making their own.

With the brakes bled and the wiring complete the next steps will be figuring out if I can access the CAN bus programming features.

There are two can bus connections. I know one pair simply provides pedal position in hex. That's for an electric vehicle to adjust regenerative brakes.

I'm mostly interested an electric e-brake button that I can use when winching. Sure the regular brake holds the rear drums. But having all four wheels clamped tight would be awesome.

-Mac

 

[macleanflood]

View: https://youtu.be/FuDEY-j7C-A?si=a3O5L94lz_dT0Wmy

 

[macleanflood]

Just got back from TJ Fest and a week of wheeling at Sand Hollow. Between the Black Magic Brakes Big Brake Kit and the iBooster I had complete control of decents... through stalling and other mistakes. Game changer for me and a confidence booster.

One trail fix I needed to do a few days in...I blew the 25a fuse and lost brakes. I replaced it with a 35a fuse and zero issues the rest of the week. I plan on moving the 12g wire to the PDC and installing a 45a fuse as recommended.

-Mac

 

[macleanflood]

View: https://youtu.be/pY0Vh_Z8xvo?si=OmKQ-Pekh8HjLkH-