So I'm working on a friends 2002 Dakota sxt ,4WD, 2 wheel abs. Originally the truck blew a brake line in the rear. Someone else replaced the line, but hooked it up straight to the rear driver side wheel. So no brake line hooked up to the other rear wheel, no prop valve, nothing!!! They also replaced the master cylinder and filled the system with trans fluid!!! That's when they called me and said we can't get the brakes to bleed. So I come over take a look at this thing get all the wheels off ,and start seeing problem after problem. The rear brake shoes are almost non existent, e brake cables cut, and as I mentioned before the brake lines hooked straight to one rear wheel and nothing else. All but one of the bleeder screws is stripped or broken off. I made the crude decision to pinch off the back line, and just have front brakes temporarily. Just until we can get the rear brakes done and hooked up right. So I tried bleeding the system from the banjo bolts on the caliper lines to try to get some improvement in the pedal. Bled all the trans fluid from the system in doing so. Still no improvement pedal feels exactly the same as before I bled it just straight to the floor. Fluid comes out steady from the calipers when bleeding. Not sure what to do to get the system to bleed. I know I probably need to get front calipers so I can bleed the system properly from the bleeders. But I feel like I should have some improvement in the pedal doing what I have done. Should I replace the calipers and try vacuum bleeding the system? I've heard it can pull air pockets out of the system that may not come out by pumping on the brake pedal. I've also seen that air could be in the abs system, and that vacuum bleeding may be able to pull the air out. This is the only idea I have really. Any advice on bleeding the system is appreciated. I'm kinda stumped at this point.

 

Fix the bleeders, or replace the calipers.... Given the system was contaminated with trans fluid, I would be real tempted to replace the master cylinder as well.

 

I wonder if the master cylinder was ever bench bled? ..... Without bench bleeding it before installing, you will never get a good pedal if any.

Knowing the previous shenanigans that took place, I would remove and bench bleed it .... even if they claim they did.
If there is any leaks such as a rusted hole in the line somewhere, will never be able to bleed them.

If the rotors are bunked up enough you cant bleed them properly .... probably just need to replace them so you can. .... Are you just trying to get front brakes so you can drive it somewhere to be worked on? ..... bench bleed MC and bleed from banjo should get you something ..... I sure would not want to daily drive this truck like this though.

My thoughts on the trans fluid .... this is bad and simply not work for brake fluid .... will not compress and can not get air out of it.
ATF will not harm rubber as there are many o rings in a transmission. Will all need to be flushed out ..... but possibly no damage was caused.
I could be wrong though.

 

So the idea was to get it to be able to drive to a shop with the front brakes bled. Let them do the rear brakes and brake lines.My friends going to get a new master cylinder, and just replace it. So if that solves the issue I'm guessing they bled the master cylinder incorrectly. Or perhaps it was faulty for whatever reason possibly the ATF put in place of actual brake fluid. Going to persuade him to replace the one caliper, so I can use the bleeder screws in the front as well. Really appreciate the help guys. I'll let you know if this works!

 

The banjo bolts are lower than the bleeders, there is ALWAYS going to be an air pocket in there, unless you fix the bleeders, or replace the calipers, you aren't going to get a good pedal.

 

Man, I've never heard of putting ATF in the brake system. Not sure what that would cause. I'd just go find a u-pull-t and pull off all replacement parts.

 

A quick search shows me that ATF eats seals in the brake system...... Anything with a seal in it, is going to need to be replaced. Master cylinder, calipers, rear wheel cylinders, proportioning valve, and hope it ain't 4wal, as that would need to be replaced as well.

 

In my younger years I tried a few times to install a MC without properly bench bleeding it .... I never got far and had to take it back off and do it correctly.

Also the vacuum pump I think is a awesome tool if you have the right one. I have a $50 hand held mightyvac 8000 .... thats not the right tool.
I have seen some videos of guys using them to bleed brakes with success .... I only got frustration trying to bleed the brakes on my truck.




While a useful tool for many things, brakes are just not one of them in my opinion .... or it could be user error. I have talked to others who had the same results.
Just a sore subject with me today because I do have a use for the tool in non brake applications .... I have a EGR valve on the bench that needs tested.
I use the vacuum gauge to time my 70 year old truck .... I need the gauge, just did not work for me on brakes.

So I pulled the gauge out of my tool chest today to use it .... it is carefully stored in it's original package and put away in a drawer .... seems the liquid in the gauge froze last winter and bulged out the body and cracked.
I got on Amazon and ordered a replacement gauge for it .... $20 + $8 shipping ..... almost $30 to repair a $50 vacuum pump
The gauge is made in such a way that you have to order a exact replacement, not a generic.

Next time I will spend more and get a better pump.

 

I have one of them fellers as well.... I never really had much success using it to bleed brakes... The "old fashioned" method of one guy sitting in the seat, and another guy going from wheel to wheel has worked every time for me though.

 

Yeah my wife has the drill down good .... go ahead means 3 pumps and hold it .... ok means let it loose .... Not saying she does not complain .... after 30+ years of marriage we make a good brake bleeding team

What pisses me off about the tool, you can see it has a liquid inside it .... I would think it would not be a liquid to freeze and expand.
My tool the only abuse it gets is a timing light in it's packaging sitting on it. While stored in the drawer.
The gauge is split up one side, across the back and then down the other side. Then on one side there are 3 more cracks that spider off the main crack. ..... To me I see a clear case of a freeze crack. ..... Just hard to believe they would use a freezable liquid inside a garage tool .... I guess I will have to start storing it inside my home office.