Brake linings

Ken Chambers

Platinum Subscriber
I'd like to bring up the discussion about brake linings. I used a local full service industrial brake relining facility a number of years ago but, while they did a superb job of bonding new linings to the Amphicar brake shoes, I've always felt that the pedal braking pressure is excessive to effectively stop the car. They arced the shoes to fit the drums and after some break-in period the shoes are now 100 percent contacting the drums. At the time I didn't request any specific type of lining material so they just did what they thought best. I just revisited the shop and they couldn't identify what type of lining was used some eight years ago based on the receipt I showed them. They said the material they use is pretty generic but the guy didn't know much about friction numbers. They did say, however, that they would install a friction material that I purchased elsewhere.

Now, researching choices of lining material, I see different coefficients of friction from which to choose generally ranging from .3 (moderate) to .5 (ultra-high) using the SAE J661 standard. Short of enrolling in an academic course to study that standard, does anyone have experience on what type of friction material is best to use?

Here's a link to one supplier with descriptions of their different friction materials. Some of their material is rigid molded shapes while other material is flexible which I presume is used for drum brake shoes. http://www.knottbrake.com/friction.html

McMaster-Carr also carries friction material ranging from low to high friction in various sheet sizes. The coefficients of friction listed appear to use the same standard. http://www.mcmaster.com/#friction-material/=tjada4

Looking forward to a lively discussion on braking.

Ken Chambers, CA
'64 Red swimmer
 

dougklink

Member
I had mine relined by brake and equipment in Minneapolis. I told them it was for an Amphicar and he said they had done them and knew what to use. I've been very happy with them, they work well dry, I just drag the brakes a little after coming out of the water and they work fine.
 
I spoke to my dad about this as he had some made by Ferodo about 10 years ago and they work very well, the process is shown in the Salvage Squad Amphicar TV show that is on Youtube. We don't have any more info and when we tried to get some more made a few years ago we couldn't find the original formula. (the Ferodo factory shown on TV had closed)
What we remember from talking to the people there is they should be rivited not bonded (glue can fail over time and water) the leading edge must be square and not chamfered. The one on the back must be shorter or Amphicar won't reverse and most important they are not abrasive. The drums are very difficult to find new and all are getting thinner, they are difficult and expensive to refurbish. In the old days when they had asbestos the shoes would wear but not the drum. As you probably know with modern cars the friction material now seems to wear the discs (rotors) so you have to replace them regularly as well - you don't want a modern material wearing the drum. Waterproof helps but more important is the material doesn't absorb water and swell when wet. Finally the original brake lining material Amphicar used is definitely deteriorating with age, we have percentage efficiency figures on our cars for the annual test here going back to the 80s and NOS shoes fitted then were much better than NOS fitted today.
 

SNOWBIRD

Amphicar Expert
You may have to search in the UK, but in Canada and the USA they can just call me and I will send out a ready to go full set of amphicar Brake shoe's, custom made to go in water, not wear drums, and tested on 100's of Amphicars since 2001.
the cost is $330.00 exchange pl, shipping. I keep a bunch here in Ontario and Ron gas a set with him in Florda.
 

jfriese

Active Member
Years ago I had a local brake place replace the linings on some Amphicar shoes. They were fine until you went into the water. After that they barely braked at all until you dragged the brakes for a couple of miles. I checked with an old line L.A. brake place and told them of my experience. He said what you need is boat trailer brake lining material. This stuff doesn't absorb water. I asked the first place about such material and they just looked blankly at me and said they always use the same stuff. Since then I've run original linings and they have been okay. I'm not sure those NOS linings would pass the strict British tests but they have worked reasonably well for me.

Actually I'm currently looking for a two pieces of full length NOS linings. Anyone who has a couple in their "spares" box and would let them go please contact me at jfriese@mindspring.com or 805-570-4778. I have almost a complete set but need two more.

Thanks,

John Friese
67 White
67 Red
 

peterboz

Member
Hi I bought a complete set lining from Germany they also fit on Mercedes If you want I can give you the brand and order number.
This are rivet lining so no glue

Peter
 

Ken Chambers

Platinum Subscriber
Hi Peter,

Yes, please do provide the information. It would be nice to be able to purchase linings ready to fit the Amphicar. Thank you.
 

Ken Chambers

Platinum Subscriber
Following up on the brake lining discussion, I spoke with Bob at Brake and Equipment in Minneapolis. Nice guy, says he's done hundreds of relinings for Amphicars. Unless a customer requests something specific, he uses a generic bonded organic type friction material with a coefficient of friction rating of slightly greater than .4, which puts it in the high range according to SAE J661 standards. Said he hasn't had any complaints from Amphicar owners. He knows about not chamfering the linings and says water immersion poses no problem except for immediately exiting the water to dry them out. They’ll also arc the shoes to fit the drums better if you supply the drum diameter. They also do a lot of cylinder resleeving for classic cars. Disclaimer: I have no affiliation with this company, just passing on some info.
to see them relining brake shoes. Their price is 17.50 per shoe, same price I paid locally here on the West Coast seven years ago. I’ve heard of other Amphicar owners using this shop. One member responded earlier in this thread that they are very happy with their brakes having used this shop. Anyone else care to report?


Speaking of friction material, here's a short Hemmings article on organic vs. semi-metallic vs. ceramic material. http://blog.hemmings.com/index.php/...-to-choose-the-right-brake-friction-material/


I just removed the linings from some original Amphicar shoes and tested it with a magnet. Definitely a semi-metallic composition. Using a strong magnet clamped to a force gauge required two pounds to pull the magnet off an OEM brake lining and seven pounds to pull the magnet off the steel backing. A good comment was made earlier that the friction material we use should not be so abrasive as to wear down the drums. Probably not a major concern early on to use more abrasive semi-metallic since replacement drums could be easily purchased.


Another comment about using boat trailer brake lining material sounds good but I can't find anything on the internet about such a thing. Anyone know of a source?


So the requirements are good friction, organic (probably) to minimize wearing of the drums, no adverse effect from water immersion, and little or no water absorption so they dry quickly. For reference, it would be nice to know manufacturer and part number of such a material. Anyone?
 
Good work Ken, we like the look of that company. Our preference is riveted instead of bonded - too many problems with bonding failing after a few years, and a softer non magnetic material to save the drums, don't care if it wears out sooner, just get them done again. Has anyone had brake hoses made there? They look closer to OEM in terms of style and quality than the other options available at the moment.
 

Ken Chambers

Platinum Subscriber
Regarding riveted vs. bonded, I guess we all have our experiences and preferences. I had a riveted Amphicar lining break apart and get jammed in the drum. The linings I just removed from a set of shoes had hairline cracks between some of the rivets. I've never experienced a bonded lining failure in any car. Seems all shoes are bonded now, at least in my experience. I've always marveled at how disc brake pads are held to their backing plates simply by a glue joint. Bonded pads and linings can wear down right into the backing plates and still the glue doesn't fail. Perhaps the bonded linings that have failed were improperly glued to begin with.

I do wonder, however, since that adhesive is so good how do brake shops deal with removing bonded linings for replacement? Must have to grind them off.
 
Maybe we have just been unlucky Ken but we have had bonded linings fail in the parking brakes of our 2005 Volvo and in the Alko brand brakes on our car and boat trailers. We were told the glues are not suitable for "classics or in-frequently used vehicles" as the glue has a design life of 10 years and also is not suitable for immersion in water. If these guys have been doing it for a long time and are aware of those issues and use different glues to mainstream we could be convinced !
Yes even some of the Energit stamped NOS linings (but, strangely, not all) have those micro cracks which kills the efficiency and I've certainly seen them being cracked if the rivets are done too tight during installation. A modern lining material may not be designed for riveting so I would raise the concern but happy to take their advice. Ferodo did use rivets for the new linings on our car in 2004 and gave a reason but we can't remember !
Other important point is to shorten the front lining on the rear drums or car won't reverse, the original Amphicar manual doesn't show that but if they have done a few I'm sure they know.
 

peterboz

Member
Ken ands the others this is a picture off the brake linings the fit on Amphicar
And are also used by members off the German Club
PeterIMG_2943.JPG
 
Thanks Peter, the German club rules are that parts are only available for members but Beral are part of Federal Mogul so those part numbers should work for other supply chains.
 

peterboz

Member
That is correct the brake linings did not come from a german clubmember but he gave me the part number so I could order it els were
 
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