Wheel cylinder Question.

After restoration my Amphi went back into use in August 2013 with all new wheel cylinders from GI. I had seen the Wheel cylinders from Belguim on Ebay and bought a full set as spares. In 2016 my front right wheel cylinder started leaking so I replaced just the front Right. Just this week I noticed my front left wheel was covered with brake fluid. (Thankfully I use silicone fluid!) So I am putting the Belguim cylinders now in the front left along with a new dual circuit master cylinder and I am sure the rears will be leaking soon also. Is this Normal, just getting a few years out of wheel cylinders? Is there anyone out there having good luck with stainless sleeves and pistons? If so, where do I get them? Wish I could make it to Celina, but cant. Thanks, Jack
 

DavidC

Amphicar Expert
Sadly some of the new production parts do fall short of OEM quality. The European cylinders you mention generally have rubber seals of the correct size (take them apart and check with your original ones) and should last at least 10 years. Changing the seals in the ones you have for genuine ATE ones is essential and might enable you to reuse them. Put an original and a repro seal side by side and you will see the issue - these are the seals that look like an O ring but with a lip - some repro ones are undersize hence leaks.
The rear cylinders are normally OK, different larger seal in there which is less critical to manufacturing tolerances.
Search on here for an article I did about red rubber brake grease to put behind the end boot, makes a huge difference, totally fixes the corrosion issue so stainless sleeves are no longer necessary. You are right to use Silicone brake fluid, I've used it in all my Amphicars and the Amphicars I've maintained for others for more than 30 years - absolutely brilliant stuff - but I don't often mention that on forums as it can start a fight !!!
 

jfriese

Active Member
About 8 years ago I had stainless steel pistons made by my local machine shop and installed them in White Post, brass sleeved cylinders that I have used for 16 years. I also used the ATE front inner seals that GI sold since they fit the tightest, and front boots that I bought from White Post, they being the only ones that actually fit tight to those small front cylinders. I packed under the boots with Red British brake grease and switched both my cars to NAPA silicone brake fluid. I was warned to flush all the old fluid out of the lines but wasn't as careful on one of my cars as the other. After about 4 years I noticed a leak in one of the rear cylinders on one car and found some black crud had built up on the brass cylinder walls. I cleaned it off, replaced the seals and two years later notice one of the right front cylinders on the same car is showing a minor leak. My other car is still perfect so I'm quite sure the black crud was because I wasn't as careful flushing the old fluid from that car and the crud is a reaction between the old fluid and the silicone. Those stainless steel pistons were so expensive to make that the cost I felt would be prohibitive so I never went into production of them. This was also around the time when GI was about to bring out their inexpensive ATE copies. Liability with a brake part was also a factor. I made 4 sets, two sets for my cars, one set for a car I restored for someone else and the forth set I sold to another owner. Be sure if you switch to silicone fluid to flush the old stuff out quite thoroughly.

I very much approve of using silicone brake fluid. If you do get a leak, it won't destroy your paint. I also like the fact that at least the NAPA silicone fluid is purple so is easy to level check in the fluid reservoir.

John Friese
67 White
67 Red
 
Last edited:

dougklink

Member
I'm the other owner. John's stainless pistons work great, I've had them three seasons and not a single issue at all. I did already have silicon in the system when I put them in, the stock cylinders froze after just one year. I highly recommend his approach. The money spent has been more than recouped with not having to mess with the brakes!
 

gzink

Member
Sadly some of the new production parts do fall short of OEM quality. The European cylinders you mention generally have rubber seals of the correct size (take them apart and check with your original ones) and should last at least 10 years. Changing the seals in the ones you have for genuine ATE ones is essential and might enable you to reuse them. Put an original and a repro seal side by side and you will see the issue - these are the seals that look like an O ring but with a lip - some repro ones are undersize hence leaks.
The rear cylinders are normally OK, different larger seal in there which is less critical to manufacturing tolerances.
Search on here for an article I did about red rubber brake grease to put behind the end boot, makes a huge difference, totally fixes the corrosion issue so stainless sleeves are no longer necessary. You are right to use Silicone brake fluid, I've used it in all my Amphicars and the Amphicars I've maintained for others for more than 30 years - absolutely brilliant stuff - but I don't often mention that on forums as it can start a fight !!!
I have owned an Amphicar for 17 years. At lease a dozen years (maybe longer) I took David's great advice, flushed fluid and replaced w/ silicon and most importantly, I believe, got the Red grease he refers under the boots of all cylinders. I have replaced a cylinder or two when they looked old (never stainless) over the years and replaced the first that ever leaked this past winter. In all this time I have not had the brake lockup issues I hear often about and I use my car more than average. If you don't trust the silicon I'd at least do the Red grease every time you service the brakes. Thanks David!
 

DavidC

Amphicar Expert
Cheers, yes it's at least a decade and about 15000 miles since I had to do anything with wheel cylinders on my car. The red rubber grease tip was given to me in the 90s by the guy who maintained the Landrovers for Landrover at their offroad course that is a few miles from here. They have a deep long "river" there and the Landies are in there for at least 10 minutes with water above the tyres - this happens a few times a day almost every day, it's very busy,. anyway they worked with Girling who make the Landrover brakes and this is where the red grease idea behind the caps came from. It's red because it's not oil based so does not affect the rubber boots. It fixed the issue for them and works great in Amphicar.

Same guy told me all about "axle suck" as Landrover people call it. This is when a hot axle from road running is quenched by water and creates a vacuum that pulls water past any seals. Amphicar thought of that with early cars and fitted the rubber cap on the front hub which flexed to equalise the pressure and stop water getting on to those taper roller bearings that I was replacing every year or two. My later car had the rigid metal cap which Amphicar fitted towards the end of production (prob because they had no more rubber ones and no interest in making them). I rigged up a rubber cap instead which helped but then encouraged Ken in AZ to make some original Amphicar type rubber caps as he had the right kit. He did and they are brilliant. Again no wheel bearing issues for many years since they were fitted. They also stop corrosion of the hub as no water is being pulled past the big oil seal on the inside. I few drops would get in and sit chewing away at that oil seal surface which was a real pain to fix. Don't know if any of those rubber caps are still available - if not some more sure be made !
 

dougklink

Member
I turned down a set of the Bearing Buddies and have been very pleased. No water ingress and easy greasing through the zerk fitting.
 

jfriese

Active Member
I had long ago heard that DavidC, and some others, had a much better experience with stock brake cylinder pistons than I had. It made me wonder if ATE made their pistons out of different "pot metals" at different times, some better and some worse.

John Friese

67 White
67 Red
 

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