Brake gooroo's

[xjallday]

Well here's the situation, I have just upgraded my 90 xj with a dana 44 and 9inch from a 79 f-150. Got all the brake lines and cables rand and then i bleed the whole system.But my brakes are still really spungy like they dont even work.I can pump them a few times and they feel fine but then when i use them to stop the brake light comes on and the pedal goes straight to the floor.I thought i might upgrade my master cylinder.Whould this help and if so what kind am i looking for i've know some people to use ones from fords and also chevy's.Thanks for all the help.

 

[PierCed_3]

Take it to a shop and have them pressure bleed your system. That's what mine took when I did the swap.

 

[grinch]

You still have air in your calipers. Its easey to get out on disks but not so easey on drums... On disks take your caliper off and find somthing about the same thikness as your rotor and put it between your pads. Turn the caliper upside down and bleed them in this position... Then put em back on and try em out.

 

[Caleb]

You still have air in your calipers. Its easey to get out on disks but not so easey on drums... On disks take your caliper off and find somthing about the same thikness as your rotor and put it between your pads. Turn the caliper upside down and bleed them in this position... Then put em back on and try em out.

no way, you want the breather up top (so if its on the bottom then do this, if its already on the top, then spinning them around is just going to get more air in there). How did you bleed them? Did you pressure bleed them (have one person pump the pedal till its hard then you crack the bleeder), or did you gravity bleed them, or did you use one of those single person brake bleeders (vaccum pump)?

 

[grinch]

no way, you want the breather up top (so if its on the bottom then do this, if its already on the top, then spinning them around is just going to get more air in there). How did you bleed them? Did you pressure bleed them (have one person pump the pedal till its hard then you crack the bleeder), or did you gravity bleed them, or did you use one of those single person brake bleeders (vaccum pump)?

No it takes 2 people to do it that way pump and hold...lol...And yes you want to do it that way when you have an air bubble in the caliper but only if you have 2 people to bleed the system so you do not get air back in the caliper....
Many moons ago I had the same problem with a dana 30 on the front of my old yj. I asked around on Priate and found out about this trick.
My father inlaw thought I was crazy when I told him this also. He had spongy disk brakes on his sand rail and couldnt get them to firm up. I told him countless times to do this and he kept thinking I was up in the night and didnt do it. I finally convinced him to try it and it worked...

 

[Caleb]

No it takes 2 people to do it that way pump and hold...lol...And yes you want to do it that way when you have an air bubble in the caliper but only if you have 2 people to bleed the system so you do not get air back in the caliper....
Inside the piston there is a small area air can be trapped. My father inlaw thought I was crazy when I told him this also. He had spongy disk brakes on his sand rail and couldnt get them to firm up. I told him countless times to do this and he kept thinking I was up in the night and didnt do it. I finally convinced him to try it and it worked... Many moons ago I had the same problem with a dana 30 on the front of my old yj. I asked around on Priate and found out about this trick.

yes, air can get trapped but all you're doing by turning it is getting that air to move...you would be better off to turn it flip it whatever but then flip it right side up before you crack it open to bleed. air moves UP...so if the bleeder is facing down there is no way you will get all the air out another thing to do is to tap the caliper...sometimes that will dislodge the air enough to get it to move...

 

[grinch]

yes, air can get trapped but all you're doing by turning it is getting that air to move...you would be better off to turn it flip it whatever but then flip it right side up before you crack it open to bleed. air moves UP...so if the bleeder is facing down there is no way you will get all the air out another thing to do is to tap the caliper...sometimes that will dislodge the air enough to get it to move...

I had to actually move fluid to get it untraped not just tap or flip it upside down... I promise turning it upside down works best. Im not trying to get into a pissig match I just know what has worked best for me. And how the good old boys on Pirate suggested to do it....

 

[Caleb]

I had to actually move fluid to get it untraped not just tap or flip it upside down... I promise turning it upside down works best. Im not trying to get into a pissig match I just know what has worked best for me. And how the good old boys on Pirate suggested to do it....

pissing match nothin...we're just having a discussion...its always good to hear new ways to do thing

 

[grinch]

good good.... Im just a sensitive little girl somtimes... Ive had this discusion a few times and people usually thinik im crazy lol... I did to the first time I herd it. But I was to cheep to go get them power bled so i had to give it a try...

 

[Tacoma]

well I still think you're crazy but I'll try a lot of stuff once..

I've had to tap a lot of calipers, almost every new one in fact...

 

[fjcruisin]

Have you checked the rear brakes? Are the shoes in good shape, adjusted properly? If the rears are WAY out of adjustment this could also cause what you described. Check that, if you want to power bleed it let me know I have a power bleeder.

 

[camicaztoy]

just had this same issue with my friends yj, here is most likely your problem. when you put your front calipers back on, there is a rt and lt side. they are not interchangeable. they WILL go on the wrong side without you realizing it. to tell if you have them on wrong, check the bleeder screws. the bleeders need to be located near the top. if they are on the bottom then switch the calipers and bleed them. your stock master cylinder is plenty strong enough to stop your new brakes. if everything worked before then it should all work now. if this isn't it then start looking for leaks somewere.