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Richard 34A · 12-02-2008, 08:52 AM

Posted the question before but still hoping for a solution. Hard to be descriptive but there is a noise coming from the brake pedal when I push down on it. The noise sounds like 'aarrraaagh' or a groan. It's not a squeek and does it every time I push on the brake. Repeated brake use in traffic makes the noise louder for a period of time. I also noticed that the brake pedal seemed to take a little more effort when applying the brake as the noise got louder.

I looked underneath (took some pictures that I will post upon approval) and can clearly see the pedal, a switch, and a cable with a rubber boot. There is a lot of white lithium grease in the area (not on the switch though) so I sprayed more but to no avail. It appears that the noise is coming from inside the rubber boot, like there is a plunger or something there inside the boot. Can the cable be lubed inside the boot, and if so, what is the techinque? Looks like the cable would have to be removed from the brake pedal to gain access but looking for some insight.

Thank you,

Richard 34A · 12-02-2008, 08:52 AM

Posted the question before but still hoping for a solution. Hard to be descriptive but there is a noise coming from the brake pedal when I push down on it. The noise sounds like 'aarrraaagh' or a groan. It's not a squeek and does it every time I push on the brake. Repeated brake use in traffic makes the noise louder for a period of time. I also noticed that the brake pedal seemed to take a little more effort when applying the brake as the noise got louder.

I looked underneath (took some pictures that I will post upon approval) and can clearly see the pedal, a switch, and a cable with a rubber boot. There is a lot of white lithium grease in the area (not on the switch though) so I sprayed more but to no avail. It appears that the noise is coming from inside the rubber boot, like there is a plunger or something there inside the boot. Can the cable be lubed inside the boot, and if so, what is the techinque? Looks like the cable would have to be removed from the brake pedal to gain access but looking for some insight.

Thank you,

TandW · 12-02-2008, 08:59 AM

You might want to check your power steering fluid resorvoir. Good luck!!

Richard 34A · 12-02-2008, 09:34 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TandW:
You might want to check your power steering fluid resorvoir. Good luck!! </div></BLOCKQUOTE>

I did check all the fluid levels just before my Thanksgiving trip, just as a habit. The noise isn't when I turn the steering wheel, but rather every time I push the brake pedal, and I can 'feel' it when applying the brakes too. But no question it's coming from inside the cab, at the brake pedal, possibly at that rubber boot or right at the firewall area.

DriVer · 12-02-2008, 11:30 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Richard 34A: </div></BLOCKQUOTE>Richard, Your brake pedal pictures have been approved. I reviewed your pictures as well.

In my experience there isn't anything that comes through the boot other than the brake pedal rod. The emergency brake motor will growl when the key is OFF anytime that you step on the brake. Is this perhaps the noise that you are hearing?

Underway the rod connects from the pedal directly to the relay rod. There would not be anything there that would interfere or rub on anything, so I don't believe it's a case of the brake rod interfering with the firewall.

The brake pedal rod translates through the relay rod which is connected to a plunger which pushes on the internal components of the Hydro-Max. When I step on my brake pedal I may hear a hissing or other remote type of noise while the pedal is applied however in of itself it does not present a problem. That noise is normal.

Does the noise exist when the engine is off?

The cable you describe is actually the shift cable. That's in you picture and runs down the steering column. There are no cables other than the emergency brake cable which connects to the rear of the transmission to a brake drum.

Richard 34A · 12-02-2008, 11:19 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by DriVer:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Richard 34A: </div></BLOCKQUOTE>Richard, Your brake pedal pictures have been approved. I reviewed your pictures as well.

In my experience there isn't anything that comes through the boot other than the brake pedal rod. The emergency brake motor will growl when the key is OFF anytime that you step on the brake. Is this perhaps the noise that you are hearing?

Underway the rod connects from the pedal directly to the relay rod. There would not be anything there that would interfere or rub on anything, so I don't believe it's a case of the brake rod interfering with the firewall.

The brake pedal rod translates through the relay rod which is connected to a plunger which pushes on the internal components of the Hydro-Max. When I step on my brake pedal I may hear a hissing or other remote type of noise while the pedal is applied however in of itself it does not present a problem. That noise is normal.

Does the noise exist when the engine is off?

The cable you describe is actually the shift cable. That's in you picture and runs down the steering column. There are no cables other than the emergency brake cable which connects to the rear of the transmission to a brake drum. </div></BLOCKQUOTE>

DriVer;

Thanks for the reply; using the picture you posted in your reply, that was only for a reference point for me.

The cable and rubber boot that I'm looking at are more under the dash; the picture was taken from the floor, looking up. The cable is attached at the top of the brake pedal arm, goes to a rubber boot, and then out through the firewall. When I push on the brake pedal, it makes the noise every time, with the motor running or not. It isn't the noise that comes from the brake system cycling and the noise isn't mechanical in nature, but rather more like something that has friction and needs to be lubed. The noise isn't a hissing sound, sort of like groan or scrunching sound. It didn't make the noise when new (currently has 14k miles on it) and only on the last few trips did it show up, and is progressively getting worse. The 'friction' is to the point that I can feel it when I apply the brakes; it has no effect on braking ability, just a loud sound that drives my wife and I crazy...

DriVer · 12-03-2008, 01:27 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Richard 34A:
The cable and rubber boot that I'm looking at are more under the dash; the picture was taken from the floor, looking up. The cable is attached at the top of the brake pedal arm, goes to a rubber boot, and then out through the firewall.... </div></BLOCKQUOTE>Richard, Although the picture is a little out of focus, are you sure that's a cable? I believe it to be a rod. In some instances owners have experienced a squealing noise with the hydraulic pump when the brakes are applied. This I understand is a type of valve issue internal to the pump.

If as you say the noise is severe and annoying I believe a trip to the service center for an evaluation may help aleve some of your concern.

Richard 34A · 12-03-2008, 10:48 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by DriVer:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Richard 34A:
The cable and rubber boot that I'm looking at are more under the dash; the picture was taken from the floor, looking up. The cable is attached at the top of the brake pedal arm, goes to a rubber boot, and then out through the firewall.... </div></BLOCKQUOTE>Richard, Although the picture is a little out of focus, are you sure that's a cable? I believe it to be a rod. In some instances owners have experienced a squealing noise with the hydraulic pump when the brakes are applied. This I understand is a type of valve issue internal to the pump.

If as you say the noise is severe and annoying I believe a trip to the service center for an evaluation may help aleve some of your concern. </div></BLOCKQUOTE>

The MH is back in storage, but maybe I can stop by in a day or so, and get a better picture. In my mind, it's a cable but I could have lost something in the translation walking in from the MH and to my computer to post my question!

Bill R. · 12-03-2008, 11:33 AM

any chance you are hearing the growl that accompanies the electric brake assits.
you would also hear this noise when stepping on the brakes with the engine off.

MikeT · 12-03-2008, 07:29 PM

I have a W20, - there isn't any cable from the foot brake just a rod thrugh the firewall. What is on the other side of the firewall?

The brakes are hydro-boost, powered by the power steering pump, that's why the checking of PS fluid was mentioned.

Sometimes you can hear the fluid "hissing". If you hear a growling, it may be that for some reason the electric motor is coming on even though it isn't needed.

John-D · 12-04-2008, 04:35 AM

On my towed (i've never noticed it on my Workhorse, but then I don't listen for it) my wife noticed a noise when she hit the brakes.. Kind of a "Cussssh" sound.

Years ago (1977) IN installed a DANA cruise control on my car, Dana later sold out to Rockewll and I don't know who makes 'em now but... That is the system that GM uses.

One of the lines hooked to the system is a vacuum dump line.. this hooks to a valve that's attached to the brake line

The sound is air rushing into this hose to make double sure the cruise control has dropped out.

That cable may be an air line (Vacuum hose)

NOTE: I later installed a newer Dana unit on a van.. it did not have that line.. but it had enough problems that perhaps they went back to the old reliable one.

Richard 34A · 12-04-2008, 06:40 AM

[QUOTE]Originally posted by John-D:
On my towed (i've never noticed it on my Workhorse, but then I don't listen for it) my wife noticed a noise when she hit the brakes.. Kind of a "Cussssh" sound.

Years ago (1977) IN installed a DANA cruise control on my car, Dana later sold out to Rockewll and I don't know who makes 'em now but... That is the system that GM uses.

One of the lines hooked to the system is a vacuum dump line.. this hooks to a valve that's attached to the brake line

The sound is air rushing into this hose to make double sure the cruise control has dropped out.

That cable may be an air line (Vacuum hose)/QUOTE]

Thanks John-D; unfortunately, this noise isn't the 'cussssh' sound, though mine does that too.

Richard 34A · 12-04-2008, 06:46 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by MikeT:
I have a W20, - there isn't any cable from the foot brake just a rod thrugh the firewall. What is on the other side of the firewall?

The brakes are hydro-boost, powered by the power steering pump, that's why the checking of PS fluid was mentioned.

Sometimes you can hear the fluid "hissing". If you hear a growling, it may be that for some reason the electric motor is coming on even though it isn't needed. </div></BLOCKQUOTE>

Thanks MikeT;

Any idea what exactly inside this rubber boot? I'm convinced, at least so far, that the noise is coming from inside the boot and since it didn't do it for the first 12k miles, I don't think it's a normal sound.

I have the 'hissing' or 'cussssh' sound too but consider that normal. This sound is not anything from the electric motor, like I would hear when the motor is off and then pump the brakes.

Richard 34A · 12-06-2008, 07:07 AM

DriVer;

You and another member are absolutley correct: there is no cable, it's a rod. Since it's brake-related and I'm no mechanic, I'll have Workhorse check out the noise. No way I want to mess with trying to get inside that rubber boot. My local Workhorse did check it out previously, but the repair order came back with 'could not duplicate' but since the noise is now far worse, I think they'll be able to diagnose it this time. It is a PITB to take in for just that, though...