| Author |
Message |
Bob D.
Samba Member
Joined: September 11, 2003
Posts: 613
Location: Chicago, IL
|
 Posted: Mon Jul 26, 2004 11:12 am Post subject: Shrieking, Squealing Brakes--Please Save My Ears! |
 |
|
For the first couple of days after installing new pads on my front brakes, all was well.
Now, whenever the brakes are used after the first couple of times each day, I get a loud shriek that lasts until the bus comes to a full stop or I lift my foot off the pedal. I can tolerate a little squeaking; I can not tolerate this level of continuous shrieking and screeching. 
Background: Pads changed 2 weeks/200 miles ago. Beck Arnley "premium" (whatever that means) pads, did use my original backing plates with tabs in good shape, and lightly sanded the rotors. Did not use any anti-squeal goop. Did no special break-in of pads, just did not stomp on them for the first several days.
Clues: Pumping lightly and rapidy on brakes before fully applying them will stop shrieking from ocurring. Applying brakes while backing up will cause the worst shrieking. Even when not shrieking, brakes make audible "hissing" sound when they are applied, previous pads did not do this.
Any advice? Is there by chance some "break-in" of the pads that I should have done or could still do? Is there a brand or type of pad that might solve this problem? Any info appreciated!
_________________
1978 7-Passenger, 37K miles
Proud Member #1, SBS (Stock Bus Society)
*Enjoy and appreciate your good health*
We used to play for silver
Now we play for life |
|
| Back to top |
|
 |
ratwell
Samba Member
Joined: April 26, 2003
Posts: 8717
Location: Victoria, BC
|
| Posted: Mon Jul 26, 2004 11:44 am Post subject: |
|
|
Beck Arnley is just a large importer of other folks parts.
When you use new pads with old brake hoses the pads don't get a chance to back away from the rotor enough and the result is major squealing. The old worn pads still had enough clearance.
_________________
'78 Westfalia CDN
'76 Doublecab
Read the Baywindow FAQ |
|
| Back to top |
|
|
Hippopotabus
Samba Member
Joined: May 27, 2004
Posts: 1600
Location: Miwuk Village, CA
|
| Posted: Mon Jul 26, 2004 11:47 am Post subject: |
|
|
Funny thing.... About a couple of weeks ago my Mechanic replaced the rear drums with new German ones. Along with that he put new pads on and adjusted the E brake. The E brake has always been a thorn in my side (never worked properly). So he made these changes and put everything together. The one thing he noticed was how the vacume plate was not the same shape as from the last set of drums I had on the bus. Because of this I've been tolerating (not very well) the high pitched squeeling and whistling. My noise generally comes when I'm going down hill and using the brake accordingly. My noise stops once I apply the breaks. Once I let off them it starts the damn squeeling again.... I'm just as confused as you. Next week I'm having him take the break's apart and find the problem. Let me know if you get resolution from working different angles.
Hippo |
|
| Back to top |
|
|
jberger
Samba Member
Joined: November 17, 2003
Posts: 2476
|
| Posted: Mon Jul 26, 2004 12:31 pm Post subject: |
|
|
| ratwell wrote: |
Beck Arnley is just a large importer of other folks parts.
When you use new pads with old brake hoses the pads don't get a chance to back away from the rotor enough and the result is major squealing. The old worn pads still had enough clearance. |
Why would old hoses not allow you to compress the pistons before you insert the pads?
How did you lightly sand the rotors? Are they smooth? If you have ridges the pads will hit these first until they break in to the rotors and it will cause squealing, chattering, and a host of other problems. |
|
| Back to top |
|
|
Randy in Maine
Samba Member
Joined: August 03, 2003
Posts: 34890
Location: The Beach
|
| Posted: Mon Jul 26, 2004 1:09 pm Post subject: |
|
|
I think the premium pads are of a harder stuff than the non-premium pads. I think the harder pads and the hard rotors are fightiung it out in there so see who can win. Volvos alll used to have that problem untill they made the rotors of softer metal + it allowed them to sell a lot more rotors..
I guess that old hoses that might be swollen might be not letting the caliper retract properly.
What would happen if you were to drive it a few blocks with a light touch on the brake pedal? That would heat them up and perhaps wear them into each other a tad faster.
Are you babying that thing too much? |
|
| Back to top |
|
|
ratwell
Samba Member
Joined: April 26, 2003
Posts: 8717
Location: Victoria, BC
|
| Posted: Mon Jul 26, 2004 1:28 pm Post subject: |
|
|
| Randy in Maine wrote: |
| I guess that old hoses that might be swollen might be not letting the caliper retract properly. |
Exactly. You can't use old hoses with new pads and expect quiet.
_________________
'78 Westfalia CDN
'76 Doublecab
Read the Baywindow FAQ |
|
| Back to top |
|
|
jberger
Samba Member
Joined: November 17, 2003
Posts: 2476
|
| Posted: Mon Jul 26, 2004 1:32 pm Post subject: |
|
|
| ratwell wrote: |
| Randy in Maine wrote: |
| I guess that old hoses that might be swollen might be not letting the caliper retract properly. |
Exactly. You can't use old hoses with new pads and expect quiet. |
What?  Do explain |
|
| Back to top |
|
|
moxnix
Samba Member
Joined: September 11, 2003
Posts: 667
Location: Mpls Minn.
|
| Posted: Mon Jul 26, 2004 1:51 pm Post subject: |
|
|
This is a very worthwhile bit of maintenance.
The rear hoses on my 70 were original ATE hoses- looked fine from the outside, but they were almost compltely plugged up/swollen inside
the shoes took several pumps to move out, and then held pressure and slowly went back.
$ 30 for both hoses and my rear brakes work awesome.
_________________
Ritterlich im Kriege, wachsam für den Frieden |
|
| Back to top |
|
|
D.Russell
Samba Member
Joined: June 23, 2002
Posts: 425
Location: Michigan City, Indiana
|
| Posted: Mon Jul 26, 2004 2:03 pm Post subject: |
|
|
| Quote: |
| Did not use any anti-squeal goop !! |
Why Not ?? Think that's why they put that in the Package ?? 
http://www.jonko.com/auto_repair/content/auto_repair/repair_QandA/brake-noise-and-squeal.shtml
From another site:
Application of anti-squeal compound on the backside of the pad backing plate can serve to prevent pad vibration, although some owners consider this "damper in a tube" a temporary measure at best. If this compound is used, it's critical to allow sufficient curing time before the brake system is used. All too often, installers apply this compound, install the pads, and immediately send the vehicle out of the shop. If the compound is not thoroughly dry and cured, it will simply squeeze out from behind the backing plate on the first brake application, rendering it useless. Apply a heavy bead on the backing plate, and allow it to completely dry before pad installation. This forms an elastic cushion that absorbs pad vibration.
Insulating shims (vastly preferable solutions to anti-squeal compound) install on the backside of the pads, between pad and caliper. Shims provide a permanent vibration damper. Shims are available for a variety of models. If their use is recommended, install them! One aspect that's often overlooked and one that can easily contribute to brake noise, involves the caliper pins or sliding surfaces. If these metal-to metal friction surfaces are dry, they can temporarily bind and chatter during operation, resulting in a squealing noise. Clean and lubricate the sides and pins with a high-temperature silicon grease. Naturally, exercise care when applying the grease to prevent contamination of the rotor and pads. |
|
| Back to top |
|
|
westy78
Samba Member
Joined: August 20, 2002
Posts: 2005
Location: Portland OR
|
| Posted: Mon Jul 26, 2004 4:36 pm Post subject: |
|
|
| ratwell wrote: |
Beck Arnley is just a large importer of other folks parts.
When you use new pads with old brake hoses the pads don't get a chance to back away from the rotor enough and the result is major squealing. The old worn pads still had enough clearance. |
I think the problem that Bob is having is just when applying the brakes though. Not a constant squeal after the pedal has been released. I had and still have the same problem. I think it might be the compound of the new pads. I replaced the hoses and rotors when I put the new pads in and my backing plates were in fine shape. They seem to be getting better as time goes by so maybe the pads and rotors are now wearing into each other.
_________________
Jasan C.
'78 Westy
VW Campmobile, it goes on vacation with you. |
|
| Back to top |
|
|
ratwell
Samba Member
Joined: April 26, 2003
Posts: 8717
Location: Victoria, BC
|
| Posted: Mon Jul 26, 2004 5:58 pm Post subject: |
|
|
| jberger wrote: |
| Why would old hoses not allow you to compress the pistons before you insert the pads?. |
They will but because the brakes are self adjusting you are back in the unfavorable position upon the first application of the brakes where the hoses have swelled internally and prevent the fluid from flowing back.
It certainly doesn't hurt to chamfer the pads slightly. That might help with the squealing on reverse which suggests a pad alignment problem in the first place.
_________________
'78 Westfalia CDN
'76 Doublecab
Read the Baywindow FAQ |
|
| Back to top |
|
|
Bob D.
Samba Member
Joined: September 11, 2003
Posts: 613
Location: Chicago, IL
|
| Posted: Mon Jul 26, 2004 8:45 pm Post subject: |
|
|
| westy78 wrote: |
I think the problem that Bob is having is just when applying the brakes though. Not a constant squeal after the pedal has been released. I had and still have the same problem. I think it might be the compound of the new pads. |
This is exactly right, Jasan. The squealing happens only when the brakes are applied. I am very pleased to hear your problem is getting better with time. Maybe I just need to apply the brakes harder for a while, or take Randy's suggestion and drive for a little bit while riding the brakes. These are the kind of corrective actions I can handle. 
Re the brake goop, right or wrong I was always told that stuff wasn't necessary if the brake system is in proper order, and that even if it worked which it probably won't, then it is merely masking a problem. Again, just what I was told as a kid and still remember 30 years later. I have not used goop or shims on any of my cars and never had a problem until now.
I believe that the prior pads were the original VW pads installed in 1978, I'm sure the new pad material is very different. Trying to find brake pads for a 1978 VW in Chicago was extremely difficult, I had to take what I could find. I wonder if higher quality pads from OEVeeDub would help this problem??
Thanks for the suggestions guys, and please post any other thoughts too. I will try whatever is posted and report back, hopefully that might help someone else.
_________________
1978 7-Passenger, 37K miles
Proud Member #1, SBS (Stock Bus Society)
*Enjoy and appreciate your good health*
We used to play for silver
Now we play for life |
|
| Back to top |
|
|
ratwell
Samba Member
Joined: April 26, 2003
Posts: 8717
Location: Victoria, BC
|
| Posted: Mon Jul 26, 2004 11:17 pm Post subject: |
|
|
If your bus is that original with so little mileage and you suspect the brake pads are factory installed parts I wouldn't be surprised if your fluid is extremely old and has contaminated the hydraulic parts of the brake system. When was it last bled?
One thing is for sure: rubber does not last 26 years. Replace the brake hoses. They may not be 100% of the cause but you cannot replace select parts of the braking system and expect it to work like new.
_________________
'78 Westfalia CDN
'76 Doublecab
Read the Baywindow FAQ |
|
| Back to top |
|
|
Bob D.
Samba Member
Joined: September 11, 2003
Posts: 613
Location: Chicago, IL
|
| Posted: Tue Jul 27, 2004 9:36 am Post subject: |
|
|
| ratwell wrote: |
| If your bus is that original with so little mileage and you suspect the brake pads are factory installed parts I wouldn't be surprised if your fluid is extremely old and has contaminated the hydraulic parts of the brake system. When was it last bled? |
Fluid was last flushed in November 2003, and the bus did receive pretty good maintenance from the previous (original) owner. As far as I can tell, the rubber parts on this bus have aged unnaturally well due to accidentally ideal storage conditions for the first 25 years (climate-controlled garage in Nevada).
I will change the hoses, but I'm guessing that hoses are probably not the cause of my immediate problem, because since the brakes are squeaking only when the pedal is depressed, it seems to me that indicates that the pads are retracting OK.
Thanks much for the explanations though Richard, as always, very helpful and appreciated.
_________________
1978 7-Passenger, 37K miles
Proud Member #1, SBS (Stock Bus Society)
*Enjoy and appreciate your good health*
We used to play for silver
Now we play for life |
|
| Back to top |
|
|
jberger
Samba Member
Joined: November 17, 2003
Posts: 2476
|
| Posted: Tue Jul 27, 2004 9:49 am Post subject: |
|
|
| If hoses are that far gone as to not allow fluid to reverse flow, wouldn't your braking pressure would be scary low. |
|
| Back to top |
|
|
steponmebbbboom
Samba Member
Joined: May 01, 2004
Posts: 6390
|
| Posted: Wed Jul 28, 2004 7:52 pm Post subject: |
|
|
| nope, the hose consists of two layers of rubber separated by braiding. The inner layer can be swollen and choking the passage while the outer layer remains intact and flexing of the hose can still be minimal. |
|
| Back to top |
|
|
jberger
Samba Member
Joined: November 17, 2003
Posts: 2476
|
| Posted: Thu Jul 29, 2004 7:48 am Post subject: |
|
|
| steponmebbbboom wrote: |
| nope, the hose consists of two layers of rubber separated by braiding. The inner layer can be swollen and choking the passage while the outer layer remains intact and flexing of the hose can still be minimal. |
If hoses are that far gone as to not allow fluid to reverse flow, wouldn't your braking pressure would be scary low. |
|
| Back to top |
|
|
Maxispleef
Samba Member
Joined: June 01, 2004
Posts: 18
Location: under my bus!!
|
| Posted: Thu Jul 29, 2004 9:14 am Post subject: |
|
|
I would recommend removing the front wheels and performing a detailed inspection of your recent brake job. Make sure those rotors aren't scored! see if you can catch your fingernail on any grooves in the rotor. Rotors will need to be measured, refinished or replaced if the surface isn't smooth.
As for your pads , make sure theyre seated in the caliper correctly, and clean the caliper mount where the pads contact. Should be free of debris, use high temp grease sparingly to lube contact points. Lastly, dont underestimate the value of anti squeal compound and vibration shims.
Volvo's require them on the rear if you don't want them to shreik in reverse!-
Lastly, I seriously doubt a internally ruptured brake hose will cause a squeak after a recent brake job, your wheel usually locks up or drags when you have a bad hose. Let us know what you find! |
|
| Back to top |
|
|
Amskeptic
Samba Member
Joined: October 18, 2002
Posts: 8568
Location: All Across The Country
|
| Posted: Fri Jul 30, 2004 12:04 pm Post subject: |
|
|
Bob,
As your brake pad replacement mechanic, I've been reading all these replies with a hot burning shame, and no small trepidation at the various paths your are being entreated to walk down. Remember my brakes? All that little squealing? My shims are perfect. My original hoses (30 years old) are fine. The spreader is fine. The pads were chamfered, the pistons were rotated to the perfect position to fit the shims, and my brakes still got embarrassingly shrilly and squicka squicka squicka as I trolled down the main streets of America. Finally, in Vacaville, CA I tried the RandyinMaine idea and got them good and hot. They quieted down. Aha, says I, must be semi-metallics that need a little work now and then. Not so fast. When they cooled down, they were worse than ever. Threw them out. Got some organic Reybestos pads in Vacaville. ALL IS WELL. I think your pad material might be the culprit. My old new pads were installed July 9th from some stuff I had hanging around my garage. The black dust that they spewed should have warned me. These new pads from Vacaville don't spew dust, are quiet, and do not change braking force depending on pad temps like those old new pads that I hate now. What brand were they? Beck Arnley.
Colin |
|
| Back to top |
|
|
Amskeptic
Samba Member
Joined: October 18, 2002
Posts: 8568
Location: All Across The Country
|
| Posted: Fri Jul 30, 2004 12:08 pm Post subject: |
|
|
| jberger wrote: |
| If hoses are that far gone as to not allow fluid to reverse flow, wouldn't your braking pressure would be scary low. |
750-1500 psi when applying the brakes, barely any just the spreader spring, when releasing. A bad hose can act like a one-way valve and cause horrid dragging when brakes are released.
Colin |
|
| Back to top |
|
|
|
