Problem ABS problems



I also have a problem and a confusion at the same time related to an ABS module.

The other day, a colleague asked me if I could diagnose his car because the ABS appears on the dashboard. I connected the diagnosis and the code was 65535 - System ok, etc.

Finally, my conclusion was that the defect would be the ABS pump. Since until now I have not had to deal with changing an ABS pump, I said I would try.

The colleague, on the other hand, found an ABS pump from someone who had a car for dismantling. So he removed the module completely (disconnected brake pipes, cables).

So that I don't have a big headache, I did the same thing with his car: I removed the pipes and the plug with cables and replaced the entire pump. Then we started to bleed the braking system.

I blew air on the right-front wheel. Everything OK. The brake held. Then I continued with the right-rear. This is where the problem started. I tried to ventilate, a little liquid came out but then nothing.

The brake pedal was soft when pressed.

I used a special pump to bleed the brakes (it is mounted on the breather plug and creates a vacuum to draw the fluid). Nothing. If he pressed the pedal, a little liquid would go, but when he lifted the brake pedal, a vacuum would be created in the system and the liquid would be drawn back... actually more air.

I opened all the pipes and checked if the pipe is not clogged. I put compressed air on the vent plug and the air came out on the HR pipe (notation on the ABS pump).

Then I mounted the HR pipe back and undid the 2 pipes that come from the brake pump on the pedal. This is where the fun started and I don't know if it's correct.

When the colleague pressed the brake pedal, a little, very little fluid came out, rather a mixture of air and brake fluid. Then when you lift the brake pedal, a vacuum is created (I put my finger and it felt like it was pulling back). In the same way, I filled the expansion tank with liquid to the maximum, up to the mouth of the tank, and when I pressed the pedal I could see how the liquid in the tank drops a little, but when I lift the brake pedal, the liquid level rises again.

I don't understand where the problem would be... Did something happen because I removed the brake pipes from the ABS module? Do I have to bleed the brake pump somehow?

From what I've seen of tutorials on the internet, they all changed only that electronic module from the ABS, they didn't disconnect the pipes even though it was more than a lot. Do I understand that I did wrong?

Now, to be honest, I don't know how to fix the problem because I have no idea why the brake pump from the pedal doesn't put in brake fluid...