Rat Rods Rule / Undead Sleds - Hot Rods, Rat Rods, Beaters & Bikes... since 2007!

Go Back   Rat Rods Rule / Undead Sleds - Hot Rods, Rat Rods, Beaters & Bikes... since 2007! > Frame/Suspension/Brake... Talk & Q&A

Frame/Suspension/Brake... Talk & Q&A All things... Frame/Suspension/Brake

Reply
 
Thread Tools Display Modes
  #11  
Old 10-30-2018, 10:59 AM
zzrodder's Avatar
zzrodder zzrodder is offline
It ain't grey hair, it's chrome!
 
Join Date: May 2010
Location: Beautiful B.C. Canada
Posts: 2,371
Default

Quote:
Originally Posted by Dr Crankenstein View Post
I would also start with bleeding the fronts. If they bleed normally, you can probably rule out the combination valve and master cylinder...

Your 6 month old pads... are they ceramic? If so, chuck those pads in the nearest orchard, cut the glaze off your rotors and put organic pads in their place. (I'd tell a long-winded story, but I'll wait for your findings.)

.
Quote:
Originally Posted by redidbull View Post
I too was fooled by the ceramic hype on my Wife's Mustang GT. Never again. Jim
Hmmmm, good question, I don't recall putting in ceramic pads but since I have CRS, anything is possible .... going to do the bleed and look at them today - is there an easy way to tell if they are ceramic?
Reply With Quote
  #12  
Old 10-30-2018, 03:29 PM
05snopro440's Avatar
05snopro440 05snopro440 is offline
Rusty Rat Rodder
 
Join Date: Sep 2012
Location: Sherwood Park, Alberta
Posts: 2,450
Default

Quote:
Originally Posted by zzrodder View Post
Hmmmm, good question, I don't recall putting in ceramic pads but since I have CRS, anything is possible .... going to do the bleed and look at them today - is there an easy way to tell if they are ceramic?
I've never dealt with ceramic pads, but could you check with a magnet or would that not work?
__________________
My 455 Buick powered '46 GMC Build Thread

My '46 GMC on Photobucket
---------------------------------------------------------------
When you don't know what you're doing, it's best to do it quickly.

And when Iím gone, you can call me foolish but hopefully not boring. I will have lived.

The more I learn about women, the more I like my car.
Reply With Quote
  #13  
Old 10-30-2018, 08:07 PM
Dr Crankenstein's Avatar
Dr Crankenstein Dr Crankenstein is offline
Rocket Surgeon
 
Join Date: Mar 2011
Location: SK CAN
Posts: 4,888
Default

Quote:
Originally Posted by zzrodder View Post
is there an easy way to tell if they are ceramic?
Quote:
Originally Posted by 05snopro440 View Post
I've never dealt with ceramic pads, but could you check with a magnet or would that not work?
A magnet will stick to the friction surface of a semi-metallic pad, it won't stick to organic or ceramic.

Organic and semi-metallic pads make black dust. Ceramic pads make very little dust... tan or light grey, depending on the manufacturer's "recipe."



By process of elimination...

- If a magnet sticks to the friction material, you have semi-metallic pads.

- If a magnet doesn't stick, you have organic or ceramic pads.

- If a magnet doesn't stick and the dust is black, you have organic pads.

- If a magnet doesn't stick and dust is non-existent (or light in colour) you have ceramic pads.


I have no idea if this post applies to your issue, zz, just sharing a friend's experience and eventual solution, which I should have explained yesterday...

A couple of years ago ,my friend (Brian) bought a very well kept, low mileage, warmed up '80 Camaro Z28. (Black on Black.) Nice car, clean as a whistle, "needs nothing". Brian put some delicate miles on the car (like it was made of glass) and everything was right in his world... a few tours went by and he soon tested its limits... goes like stink... stops like a lingering chili fart...

Brian (a good backyard mechanic) tore his hair out chasing the problem... he went through the brakes over and over again, only to discover he had "brand new" ceramic brake pads that couldn't cut the mustard. "Glass on glass" was his description... pedal feel never changed, but the car now stops like it should on conventional brake pads.

Again, I have no idea if my ramblings apply, just sharing what my friend experienced and the (unbeknownst) easy solution to his problem...

.
__________________
- The distinction between psychological illness and creative thinking is wafer thin -

1937 Chevy Coupe
1938 Chevy Sedan
Reply With Quote
  #14  
Old 10-30-2018, 10:59 PM
zzrodder's Avatar
zzrodder zzrodder is offline
It ain't grey hair, it's chrome!
 
Join Date: May 2010
Location: Beautiful B.C. Canada
Posts: 2,371
Default

Good info Doc, thanks. I'll do the magnet test / dust exam in the next couple days. Today I bled the fronts, didn't seem to spit out any air but they did take a few goes to get it flowing. Doing it solo with a 2x4 between the pedal and the seat to hold the pedal down so that may have limited the amount of fluid coming out on each try.....
Took it for a 2 mile test drive and did several hard stops (on blacktop) - not able to lock up any wheels but it stopped straight every time and in a normal distance. Front rotors were hot and drums were very warm, nowhere near as hot the other day when they were squealing. So now I'm a bit puzzled, did the bleeding fix it?? I did whack the calipers back and forth while the wheels were off - they seem to be very stiff in their mounts on the spindles. These Ford calipers are held in place with a metal block, spring bar and retaining bolt. I'm wondering if the calipers are just not floating properly on their mounts, not letting them move around as the brakes are applied? Should the mounting points be lubed and if so what is the right stuff?
Reply With Quote
  #15  
Old 10-30-2018, 11:33 PM
MercuryMac's Avatar
MercuryMac MercuryMac is offline
Builder Junky!
 
Join Date: Jan 2013
Location: Northern Alberta, Canada.
Posts: 2,424
Default

ZZ, your stiff caliper piston suggestion has awakened me. I am changing my wife's Explorer rear brake calipers, because the pistons seized into the calipers. You may be onto something there. Good luck.
Reply With Quote
  #16  
Old 10-31-2018, 05:31 PM
akatao akatao is offline
Rusty Rat Rodder
 
Join Date: Aug 2013
Location: mass.
Posts: 421
Default

I have always lubed the slides usually with what is called caliper lube that not being available I have used never sieze .
Reply With Quote
  #17  
Old 10-31-2018, 10:07 PM
zzrodder's Avatar
zzrodder zzrodder is offline
It ain't grey hair, it's chrome!
 
Join Date: May 2010
Location: Beautiful B.C. Canada
Posts: 2,371
Default

Quote:
Originally Posted by MercuryMac View Post
ZZ, your stiff caliper piston suggestion has awakened me. I am changing my wife's Explorer rear brake calipers, because the pistons seized into the calipers. You may be onto something there. Good luck.
In my case, it's not the pistons seizing up, it's the mounts that the caliper sits in that is holding it too tightly.

Quote:
Originally Posted by akatao View Post
I have always lubed the slides usually with what is called caliper lube that not being available I have used never sieze .
Thanks, I'll check those things out.
Reply With Quote
  #18  
Old 10-31-2018, 10:44 PM
BlueNorther BlueNorther is offline
Rusty Rat Rodder
 
Join Date: Sep 2012
Location: Saint Cloud, Minnesota
Posts: 502
Default

those are "sliding abutment style" front calipers, these work OK as long as you lube the **** out of them.

I used a EP wheel bearing grease (extreme pressure), along with taking a coarse flat file to the groove and all the surfaces on the caliper and mount touched by the slides and the anti rattle spring ( that funny curved "flat" spring thing).

when lubed and filed clean they only move about .002" - .004" each time you apply pressure.
Reply With Quote
  #19  
Old 10-31-2018, 10:51 PM
Dr Crankenstein's Avatar
Dr Crankenstein Dr Crankenstein is offline
Rocket Surgeon
 
Join Date: Mar 2011
Location: SK CAN
Posts: 4,888
Default

Quote:
Originally Posted by zzrodder View Post
I'm wondering if the calipers are just not floating properly on their mounts, not letting them move around as the brakes are applied? Should the mounting points be lubed and if so what is the right stuff?
You might be onto something and more. Since you posted this thread, I've read and understand a good shock to the combination valve can reset the valve to its "neutral" position, at least until it sees irregular front/back pressure again...

Anyhow, if your calipers were not floating freely, I surmise your "hits" and panic stops freed the calipers and re-educated the combo valve.

When I do a brake job, I slap some anti-seize compound on every metal to metal contact. High-tech geeks may disagree, but I've used common, general purpose anti-seize since I knew how to spell it...






.
__________________
- The distinction between psychological illness and creative thinking is wafer thin -

1937 Chevy Coupe
1938 Chevy Sedan
Reply With Quote
  #20  
Old 11-01-2018, 09:56 PM
zzrodder's Avatar
zzrodder zzrodder is offline
It ain't grey hair, it's chrome!
 
Join Date: May 2010
Location: Beautiful B.C. Canada
Posts: 2,371
Default

I took BN's advice and took the calipers off, filed, wire brushed and lubed all the contact points between the calipers and mounts - you can see how rusty the mount is in the first pic. I used a specific lube for brake parts, high silicone that won't melt off. things seemed to go back together easier, I'm pretty sure this is where the problem is. Oh yeah, the magnet test confirms they are metallic pads, not the dreaded ceramic.
Naturally, the insurance just ran out end of October, if the rainy weather now hanging around now lets up I'll get a short term permit to get in a couple end of season drives before heading south for the winter.



It occurs to me that when I installed the new pads last season, I compressed the caliper pistons with a C Clamp but did not remove the MC reservoir cap (didn't want to spill brake fluid on the paint.) - maybe it upset the prop valve and now bleeding and messing with things has reset it like Doc surmised . Fingers crossed that it's OK now. Thanks again everyone for the advice.
Attached Images
File Type: jpg IMG_1083.JPG (99.0 KB, 22 views)
File Type: jpg IMG_1084.JPG (97.7 KB, 23 views)
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 02:48 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Rat Rods Rule Inc.