[BigDad]

I have finally gotten around to addressing my ABS light. Light went on at 60,000, took it in, outrageous cost to repair. Have driven for almost 100,000 after that. (my thinking, never had ABS before, I can do without it now) I decided, now that I'm retired and working on the truck more, I would look into fixing it my self. Pulled the codes, (with a jumper) and 3 of the 5 systems are bad! And you can only pull 3 codes at a time. Cost in parts is still ridiculous. I have decided to delete the ABS pump and replace the master cylinder, with an older 3 port output, (the ABS mc only has 2) Basically turning the braking system, back to a 2000. Looking for people to find flaws in my plan.

 

[Hertz]

I’m interested in this. Mostly because I have the same scenario as you.

Do you think it will be any different than the system being disabled when it sees a problem (which is what happens now)? Other than removing the pump as a potential place to get air in the system I can’t really see any benefits.

 

[smj999smj]

Unless the ABS pump is leaking, why not just unplug the ABS control unit and leave the pump and master cylinder alone? That said, my personal recommendation is to repair the system. The fact that you haven't needed yet doesn't mean that someday it won't prevent you from getting into an accident or other bad situation, if you were to have it fixed.

 

[BigDad]

I think it's a possible cause of some air getting the system, that I don't get a firm pedal, on the first pump, perfect on the second, and no other real culprit. As far as repairing, unless you buy from Nissan some parts are not even available. When I pulled codes, I had a bad pump, used $150 eBay, new Nissan $750. Rear speed sensor even from rockauto is $270, I don't remember what the third code was, but it will only pull 3 at a time. Doesn't seem worth it to me, been driving for 45 years this was the first vehicle I ever had with ABS. Replacing the master cylinder and plumbing a few brake line for about $50, Then if I can get rid of that annoying ABS light, I'll be happy.

 

[smj999smj]

As far as the pedal, make sure your rear brakes are not in need of adjusting, because that will cause that, as well. Usually if you have a leak causing air in the system, the pedal will gradually sink to the floor as you keep pressure on it.

 

[BigDad]

As far as the pedal, make sure your rear brakes are not in need of adjusting, because that will cause that, as well. Usually if you have a leak causing air in the system, the pedal will gradually sink to the floor as you keep pressure on it.

There is no doubt that there air in the system. When I did a vacuum bleed, I got bubbles from FR, like it was a bad leak. There is no leak, if air could come in, fluid would go out, no leak. I have a gear head buddy down the street, he had the theory, "That there was no leak with positive pressure (brake pedal) but a caliper seal could leak under negative pressure (vacuum bleed) . I guess new calipers are in order, they are original. Thanks about the rear brake thing is on the slate, even though no problems. But either its the caliper thing, or the abs pump is letting, and sealing the air in. That's why the possible delete, to simplify. Thanks again.

 

[smj999smj]

How familiar are you with using vacuum pumps? I've used them for over twenty years and you will almost always get air bubbles in the fluid you pull out when you bleed the brakes. It will pull the outside air past the threads of the bleeder valve, so it looks like there is air in the system when there isn't. If you remove the bleeder screw and put some silicone grease on the threads and re-install it, it will help, but is still not guarantee.

 

[BigDad]

How familiar are you with using vacuum pumps? I've used them for over twenty years and you will almost always get air bubbles in the fluid you pull out when you bleed the brakes. It will pull the outside air past the threads of the bleeder valve, so it looks like there is air in the system when there isn't. If you remove the bleeder screw and put some silicone grease on the threads and re-install it, it will help, but is still not guarantee.

Thought about that, did a few things to stop that, but it does only happen at the one wheel, and again it acts like there is air in the system. My plan is to do a pressure bleed, since I have no fluid leaks under brake pressure, and see what happens. After that probably new calipers, and though the rears are worn (a little more than 1/4" left) and seemed to be adjusted properly, I'll probably do the rears at least none of these things are that expensive.

 

[smj999smj]

It sounds like a plan!

 

[Blackjacks Garage]

It sounds like a plan!

Have an issue with rear brakes not bleeding. Replaced shoes, replaced LSU. LSU will bleed fluid but not the rear brakes. I'm thinking that the wheel cylinders may need replaced. Any info on this would be great thanks

 

[tomgilco2]

I think it's a possible cause of some air getting the system, that I don't get a firm pedal, on the first pump, perfect on the second, and no other real culprit. As far as repairing, unless you buy from Nissan some parts are not even available. When I pulled codes, I had a bad pump, used $150 eBay, new Nissan $750. Rear speed sensor even from rockauto is $270, I don't remember what the third code was, but it will only pull 3 at a time. Doesn't seem worth it to me, been driving for 45 years this was the first vehicle I ever had with ABS. Replacing the master cylinder and plumbing a few brake line for about $50, Then if I can get rid of that annoying ABS light, I'll be happy.

I usually cover my warning lights with black electrical tape and keep on trucking.

 

[tomgilco2]

I usually cover my warning lights with black electrical tape and keep on trucking.

I usually cover my warning lights with black electrical tape and keep on trucking.

Is it feasible to bypass those horseshoe shaped brake lines?