Why is my Isuzu NPR brake pedal not working?

Why is my Isuzu NPR brake pedal not working?

If the vacuum pump was bad the brake pedal would be extremely difficult to press down. You have air in the lines and the hotter your brake lines get, the softer the pedal gets. Bleed your lines properly. What year truck? Which engine? It is amost never a master on an Isuzu. Check for air. If you remove the grill there is two rubber hoses.

When does the brake booster light come on on an Isuzu?

On an NPR isuzu, if you hit the brake, the brake booster light comes on. Usually comes on after 2 pumps on the brake. This test is at an idle in park. Also noticed there was no resisting pressure.

Are there any brake issues with the Isuzu?

Isuzu NPR brake issues.. anyone familiar…. My brakes were scary soft and replaced the master cylinder. Now about two times a day out of nowhere, when I apply my brake pedal it goes straight to the floor. Scared the SHIXNIT out of me. After releasing the pedal it returns to normal. Anyone ever have this issue or know what might be causing it?

Can a vacuum pump cause a NPR brake issue?

Diesel npr’s have a belt driven vacuum pump on the engine for the brake booster, and when the vanes get weak it can cause that problem, at least that’s what it was on the one I had. magicwand… “vanes”?? what are those.

On an NPR isuzu, if you hit the brake, the brake booster light comes on. Usually comes on after 2 pumps on the brake. This test is at an idle in park. Also noticed there was no resisting pressure.

If the vacuum pump was bad the brake pedal would be extremely difficult to press down. You have air in the lines and the hotter your brake lines get, the softer the pedal gets. Bleed your lines properly. What year truck? Which engine? It is amost never a master on an Isuzu. Check for air. If you remove the grill there is two rubber hoses.

Isuzu NPR brake issues.. anyone familiar…. My brakes were scary soft and replaced the master cylinder. Now about two times a day out of nowhere, when I apply my brake pedal it goes straight to the floor. Scared the SHIXNIT out of me. After releasing the pedal it returns to normal. Anyone ever have this issue or know what might be causing it?

Diesel npr’s have a belt driven vacuum pump on the engine for the brake booster, and when the vanes get weak it can cause that problem, at least that’s what it was on the one I had. magicwand… “vanes”?? what are those.

How can I tell if my Isuzu NPR is working?

When you pull up on the wiper lever, that activates the exhaust brake. The light on the dash has to be on for it to be activated. And “IF” everything is working right, the brake will come on while you are driving along, you let off on the gas pedal. You will hear a “whooshing”sound. That tells you it is working. Not sure about the tranny light.

Why does the NPR pedal go to floor first time?

Re: 05 isuzu npr brake pedal goes to floor first time and… I’ve found on vehicles with drum rear brakes, if the rear brakes aren’t adjusted correctly, the pedal must be pumped up to get good pedal. The reason is you have to make up the distance from the shoe to the drum before the pedal builds pressure in the system.

What causes mushy pedals on self adjusting brakes?

Self adjusting brakes can be worse. Worn/loose front wheel bearings can push pads back and cause a similar mushy pedal. Check for leaks, check adjustment, bleed before condemning any parts. Bad booster or pump=rock hard pedal. Bad master cylinders usually won’t hold a pedal. If it pumps up, it will sink.

Where is the booster on a 2004 Isuzu NPR?

Check inside the cab at the booster and see if there is a black booster mounting to the rear of the master cylinder and if it has a line to it please. Just want to make sure this one has the vac booster or the hyd one. Thanks Can you change the vac pump or is it built into the alternator?

What are the problems with the 2002 Isuzu NPR?

2002 Isuzu npr hd brake problems Exhaust brake light shuts off on its own and brake pedal comes hard as a rock already bled the brakes change a brake booster change the vacuum pump and problems still …  read more Mike Mcmillan Triage Tech/Shop Foreman