1997 Qx4 Braking Issue!

[qx4crow]

Hi, I'm new to the Nico forum, I've read alot of posts since recently buying a 1997 qx4.
I hoping some of you can help me out with some issues I'm having.

First. I bought the qx4 without being able to drive her, "bad stater.. turned out just a lose battery connection" thankfully the the owner was honest about the vehicle and told me everything she needs and some more.

The main problem I having is with the brakes. When I push the pedal it travels to the floor before it starts to bite, If I pump them 2-3 times it brakes great and hard.
Today I replaced the Master cylinder "former owner said that's what is needed" and bleed the brakes, although I didn't know of the lsv valve? I bleed the front and back and seen no air "fluid flowed good"

Went for a test drive... and nothing changed.. out $240 for the master... as I can not return the part..
I pulled the hose to the booster and checked the the line, vacuum air sucked hard.
Im out of ideas on whats causing the brake pedal to act this way?

Really thinking the abs pump? The abs light is on. I pulled the two small relays.. but No change..

any ideas? thx

[Towncivilian]

Is your QX4 4WD? If not, you don't have a load sensing valve. If you do have 4WD, bleed again using the correct bleeding order (found in the general info thread linked in my signature). Did you bench bleed the master cylinder before installing? What brand is it? Are the rear brake shoes in adjustment?

I will post instructions on pulling the ABS system codes tomorrow; I'm on my phone at the moment, sorry.

Welcome to NICO.

[qx4crow]

Thanks Towncivilian, After reading a fair few posts on here I had a feeling you'd be first to reply
It is a 4x4, I did bench bleed the Master, But I'm now thinking it did it wrong as fluid only came out of one of the holes where the brake lines go into..
Do you know the location of the LSV?
I'm not sure of the brand ill check tmw.
I don't know what/know to adjust shoes..

Do you know if the abs pump pressurizes the system. I was thinking of replacing it, due to the light being on..

[Towncivilian]

The LSV is above the rear differential.

The ABS pump does not pressurize the system unless ABS is engaged, as far as I know. I would not jump to conclusions until you pull the ABS codes. Still on my phone so I can't find the page number of the FSM that has instructions and description of codes yet, sorry.

[qx4crow]

No prob, I find something about pulling abs codes, but it says to ground port hole 9?? Will an OBD2 reader pull the code?

thanks again.

[Towncivilian]

An OBDII reader won't pull ABS codes, unfortunately. You need to ground the pin, unless you happen to have access to a CONSULT-II.

[qx4crow]

No consult -|| ... I'm going to try n re-bleed the mc and brakes tmw..
So lsv first.. Then front fellowed by back brakes to bleed?

I'll let ya know

[fastpakr]

For 1996-1997 models:
1. LSV air bleeder (Models equipped with LSV)
2. Left rear brake
3. Right rear brake
4. Left front brake
5. Right front brake

[Towncivilian]

Page BR-44 of the factory service manual has instructions on pulling ABS codes. Pull them and post them here.

[qx4crow]

Awesome, But how to i "ground it out"? with a nail? thumb tac?

[Towncivilian]

Metal paper clip, ground it with a black wire. Or maybe a multimeter lead.

[qx4crow]

**Update ** I went to a mechanic friend of my who owns a shop, He started by taking off the back drums and checking for leaks and if they work.. no leaks and rear brakes work fine. Then we flushed the brakes three times and still no difference, when manually pushing the brake pedal down i could see a nice clean jet of brake fluid coming out of the line
The mechanic truly believes the new master cyl I bought is a dud...

We did the bleed in the right order expect he refused to bleed the lsv, said the fluid splits there and goes to the rear brakes??
also he believes its the master cyl is the problem.. due to the fact after i pump up and the pedal gets hard, if I hold pressure on the pedal it goes back down to the floor.

any more ideas? expect buy a new one?

[Towncivilian]

Bleed the LSV first. It is listed in the factory service manual for a reason.

Test your brake booster following the instructions on BR-15.

[qx4crow]

Thx town, Tested the booster and it works good. So I bought a used MC at the junk yard "$24cdn" even better returned the new one for a refund "$259cdn" ... still in shock of the mark up on them ..
The new "used" MC has seemed to help.. Bleed the lsv first, then the brakes in the right order, Definitely has helped, brakes will lock up on first push, although I'm going to bleed them one more time

I do have another question... have you ever replaced a c.v. joint, and or ball joints in the front?

Thanks so much for your time, be totally lost without your reply's

[Towncivilian]

I've never had to replace ball joints yet, and my Pathfinder is 2WD so I don't have C.V. joints.

Make sure your rear shoes are in adjustment too, they are responsible for much of the pedal feel. I'm glad a used MC and proper bleed order has helped.