Z32 Abs delete

I have a 1990 300zx with an LS Swap. Abs was deleted and I just have the 2 lines from bmc going to front and rear split. All plumbing for abs was removed. My front brakes keep locking up. What do I do? Thanks

 

I have never had a problem,sorry i cant help you.

 

My understanding is that you would need a Non-ABS bmc which is 3 outs. 1 for rear and 2 for front left and front right. As the ABS unit would have done the specific brake proportioning.


GK tech sells BM57 brake master cylinder for Z32

 

Awesome. Thank you. Do you think i would also need a combination proportioning valve?

 

If you're running standard Z32 brakes, no you wouldn't need it.

Both ABS and Non-ABS have proportioning valves, but the 3 port one caters for both front calipers.

 

So what is it then about the 2 line bmc that is causing the front to lock up? Is it the fact there's only one line going to front and back as the bm57 splits the front into 2? Thanks

 

With your current bmc the fronts have too much force applied. So they lock up. The rears don't naturally lock up as they are a smaller caliper with less clamping force. Obviously if you slam on the brakes on non-abs they will all lock up.

 

You will be better off to fit an adjustable proportioning valve. The ABS usually controls unwanted lock up but you don't have that.

 

Whats you caliper condition like?

Using a non abs master will help update the condition of the brake master system, from memory the bore and stroke are the same between allot of the earlier ones. They changed it up a little later in the model release.

Typically if the ABS was deleted doing the replumb works fine as the module is what controls line pressure between each corner as needed.

Overall brake force applied by the master is the same.

If youre finding the fronts locking up i would investigate caliper condition and check that the pistons are clean and free in their movement over the stroke.
I wouldnt be surprised if your issues are there.

Worst case you can install a line splitter and dial in your desired brake forces, eg like a rally car.

 

First, ensure there’s no air in the brake lines or system, as that can cause uneven braking. Check the master cylinder and proportioning valve to ensure they’re properly adjusted for your new setup, as the LS swap could have altered brake pressure. If you haven’t already, consider adding a bias valve to control brake distribution between front and rear, which may help prevent the front brakes from locking up.

 

Also check the wheel bearings on the front wheels. Worn or damaged bearings can cause the wheel to wobble, which might lead to uneven brake application and locking. Make sure the bearings are in good condition, properly lubricated, and not causing any issues with wheel movement.