Getting a clacking noise when I apply my brakes

[BARRACUDA1968]

Just put in a new motor and been driving around listening for any noises. When I slow up to a stop sign and apply pressure to my brakes I get a clacking noise. If I let of the brake it goes away.

I'm not familiar with the brake systems on these cars so I need a little help here. The sound comes from the dash/firewall?

 

[mikestertwo]

Does the car still have the electric powermaster brake system on it? The noise could be coming from the pump motor.

 

[BARRACUDA1968]

Does this help?

 

[whitehot1]

Yep thats the powermaster brake system.

Another bad design on these cars, like the charging system that when the bulb burns out the alternator won't charge the battery.

The powermaster brake system has a fuse that when it blows the brakes don't work.

The cure for the powermaster brake system is the vacuum brake conversion.

 

[BARRACUDA1968]

Thanks for the information. I'll do a search for the brake conversion.

 

[ravege]

Had the drums apart lately? I had this exact problem and it was the adjuster not put back in right.

 

[whitehot1]

If you do decide to keep the powermaster brake system. Here is a link for some info that may help you with them.

http://www.gnttype.org/techarea/brakes/PwrMstr.html

 

[BARRACUDA1968]

No I have never had the drums off since I've owned the car.

I just put a new motor in the car a few days ago and the brakes have never done this before. I went full hydraulic roller so you can imagine what was going through my head when I started to hear clacking rolling up to stop signs.

I will check out the link! Thank you.

 

[Jerryl]

Thanks for the information. I'll do a search for the brake conversion.

30% suggest keeping the PM, 30% suggest vacuum, 30% suggest hydroboost, 10% suggest manual brakes. Happy searching. Lol

 

[TurboDave]

The clacking sound if coming from the powermaster could be the pump rapid cycling, possibly due to a bad pressure switch. The best resolution at this time would be a new modern accumulator (they don't fail), and a new pressure switch.

 

[Pronto]

Never head a powermaster make a clacking. Typical noise is the electric motor running continuously. Does it make that noise when you first start the engine?

 

[TurboDave]

Never head a powermaster make a clacking. Typical noise is the electric motor running continuously. Does it make that noise when you first start the engine?

Depends on how accurate his sound description is. Mine made a sort of clacking/clicking sound when the last pressure switch was failing.
Fortunately the newest cardone accumulators have suffered no failures since thier introduction several years ago. Cutting the powermaster failure rate by a huge percentage.

 

[whitehot1]

Another thing to consider in keeping the powermaster brake system along with safety is the cost of the parts compared to the vacuum brakes. If you value your life and your car then the vacuum brakes are the way to go.

The powermaster brake system is good when it works. But the 2 times it stopped working for me it never gave any indication before it quit and i had no brakes,on 2 different cars.

 

[BARRACUDA1968]

30% suggest keeping the PM, 30% suggest vacuum, 30% suggest hydroboost, 10% suggest manual brakes. Happy searching. Lol

I hear that!!! I've been searching around for opinions on re torqueing heads after a few heat cycles. After reading all the treads I found on a google search pertaining to our cars I'm dumber than when I started. Of all the people who claimed to talk with ARP not one person who claimed to talk with ARP gave the same answer.

I do not hear the noise when I first start the car. Only when I apply the brake with enough pressure to get the car stopped for a stop light or make a turn. If I coast the brake anticipating stopping I don't hear the noise.

I will probably just upgrade and fix the brake system I have if they have better parts available now. I'll probably start with the pressure switch mentioned earlier by Turbo Dave.

 

[Pronto]

I guess if it is cycling quickly there could be ticking from the pressure switch failure. My switch failed by leaking through the housing. No odd noises just a little dripping.

 

[charlief1]

Really guys? Anyone remember the KISS method? Pull your front wheels off and then the calipers. The outer pad is most likely sliding back and forth causing the clicking sound. The outer pad has "legs" on top that are supposed to hold it in place on the caliper. To install then correctly you need to "tighten" them up so they don't move. I'd bet someone didn't do this when the pads were installed so the pads are rocking in the caliper when you hit the brake pedal. Very common 80's GM brake issues and I can't remember how many thousands of these I've delt with over the years.

 

[Pronto]

That's certainly possible. We focused on the powermaster b/c he said the noise came from the dash/firewall.

 

[BARRACUDA1968]

Good information I can check that out.

I have no experience with this on a GN but I own a used car dealership and have done hundreds and hundreds of brake jobs over the last 18 years and I would think the condition you're describing would be felt in the brake pedal if the pad was moving around. My brakes are smooth as silk, I just have a clacking noise from the dash firewall area. With respect I doubt it's in the rotor, caliper area.

I do thank you for the insight because you never know.

 

[charlief1]

Since it's in the dash area the other thing to do it put some grease on the rubber bumper where the hood comes down at the wind shield. That can also cause a clicking noise.

 

[BARRACUDA1968]

That's another good point. My hoods been off since November and we put it back on 4 days ago and adjusted it so it lines up nice. It may be tight at the cowl. To get it lined up nice I pushed down on the back of the hood and tighten'd the small adjuster bolt. I may have it a bit tight.

I also have the old red HR motor mounts so from what I'm told they will transfer vibration more than the newer style.