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Fri Oct 01, 2021 12:04 pm

aeromech wrote: Send a link Ray and I’ll let you off the hook

Here is some 7mm brake hose. https://www.belmetric.com/brake-hose-oem-c-14_844/?zenid=1794nbk09fpivj5c0j3lggbdu7

Fri Oct 01, 2021 12:48 pm

Abscate wrote: I use Tygon for brake bleeding amd with just that short exposure I have to clip the end off the next time I bleed.

For constant contact, EDPM hose only.

Yep....also understand....Tygon (St Gobain brands)...is just a brand/family trademark name....and not an actual material descriptor. You can get "Tygon" tubing in about 10 different materials.

Aeromech said:

Quote: I posted that in like 2014 and have used the gates hose several times. I just recently got some feedback that the gates hose had swelled. He said he thought that brake fluid had gotten into the sidewall somehow. I trust the guy who said this so I’m passing along this info. I’m looking for a good substitute but doubt Tygon tubing would work just because it’s so easy to find I figure that if it was the solution, I would already be using it.

Yep....your quote did not make total sense until I looked at the link that was posted.

So....not beating on Bel-Metric. If a company that is selling a product "states"...thats its suitable for DOT 3 and 4 brake fluid ....one would hope its all good....right?

My worry with some of what I see in that add........and reading Aeromech's quote above.....look at the 3rd hose down in that ad from COHLINE.

It seems to say the right thing. EPDM on the inside....ok.....but on the outside where they have aramid fiber scrim (yeah thats good).....is it the same rubber on the outside? If its not EPDM or silicone.....brake fluid will eat it....and the outer layer will bulge and can cause the two layers to peel apart.

The top hose...by Continental ....appears to be one total rubber cross section with the braiding applied to the outside. While it makes no mention of EPDM....Continental is not stupid. One would think they know after about 100 years...what rubber it needs to be made from.

The blue hose in the middle is made the same way....but I have no idea by whom.

The other possible issue is that .....these damn products are made all over the globe. Though the brands "SAY" Cohline and Continental.....are they possibly made by "CH- ohline" or "CH-ontiental" ?.....and maybe NOT the right rubber type? Hmmmm...who knows.

There have been issues....."product of Germany" versus "Made in Germany". I "think" product of Germany means ...made with world materials...or partially made....of maybe even in "Ch-ermany".... :wink:

Ray

Sat Oct 02, 2021 8:37 am

I've used Subaru heater hose and its worked great for years . Not sure what that is made of, but its multi-layered and unlike any other heater hose I've seen. Only OE Subaru .

Sun Oct 03, 2021 1:46 pm

Manfred58sc wrote: I've used Subaru heater hose and its worked great for years . Not sure what that is made of, but its multi-layered and unlike any other heater hose I've seen. Only OE Subaru .

It very well could be either EPDM lined or EPDM all the way through...for antifreeze. EPDM has pretty high temperature range and is perfect for glycols, most common alcohols, glycol ether etc.

Ray

Tue Oct 05, 2021 7:09 am

Makes sense, I'm not trained in any way with material science but like to learn as I go. I'll pull some info off the heater hose.

Fri Jun 17, 2022 12:50 pm

For what it's worth, the part sold for this application works well, I would advise to use that instead of sourcing an unverified hose material. Links below for JBugs, but most retailers should stock it.

On an early bay, use this hose:
https://www.jbugs.com/product/211611805E.html?rrec=true

And these hose grommets for a good seal at either end.
https://www.jbugs.com/product/211611833C.html

The hose was slightly too long for my application ('70 bay) but I trimmed about 3" off of the top side and flared the cut end with a heat gun and socket. Very easy to do. The excess length was routing the tube into the path of the pedal linkage, but now it clears easily. I also put clamps on both connections to be safe.

They sell this hose for later bays as well. Just wanted to share in case it could help someone searching for a replacement.

Fri Jun 17, 2022 2:06 pm

I just redid the brake system on my 68. If you are sticking to the stock 68 only setup, you need 1/2" epdm hose, around 6 inches of it. I found this at my local Tractor Supply Store (see link below) in stock. It's more than I need but I didn't have to wait for shipping. Used a couple of fuel injection style hose clamps on the ends. Been on there a little over a month and no swelling, cracks, drips, hardening, etc. That clear tubing from JBugs is really for the 69 and up setup. However, the replacement lower reservoirs that are available are for the 69 and up but they also fit the 68 as the 68 only lower isn't reproduced by anybody.

Also, to use the JBugs tubing linked above, you need the 69 and up upper reservoir. The upper reservoir on a 68 is also 68 only.

https://www.tractorsupply.com/tsc/product/abbott-r..._vc=-10005

Mon Jan 15, 2024 3:51 am

raygreenwood wrote: EPDM.....now you now what it is. Ray

have to be other materials that can tolerate brake fluid - NBR, SBR, PU, PA, PVC, neoprene, silicone.. synthetic rubber (whatever that is)..? is EPDM really the only one?

brake fluid - with the exception of DOT5 - is basically diethylene glycol (is that right? i'm no chemist). a number of materials should be able to cope - here's a great resource to check compatibility: https://mykin.com/rubber-chemical-resistance-chart-2

Mon Jan 15, 2024 8:52 am

daos wrote: raygreenwood wrote: EPDM.....now you now what it is. Ray

have to be other materials that can tolerate brake fluid - NBR, SBR, PU, PA, PVC, neoprene, silicone.. synthetic rubber (whatever that is)..? is EPDM really the only one?

brake fluid - with the exception of DOT5 - is basically diethylene glycol (is that right? i'm no chemist). a number of materials should be able to cope - here's a great resource to check compatibility: https://mykin.com/rubber-chemical-resistance-chart-2

Yes, I have been posting links to the Mykin list for eons. It's one of the most complete.

Diethylene glycol is only one ingredient in DOT 3/4 brake fluid so don't be searching by single ingredient or you will mess up! The list at Mykin....specifically has a listing for brake fluid (DOT 3 glycol type) on page 1.

On one hand....yes a number of materials can cope with brake fluid....but only a few are rubber or flexible.

Back to your short list:

NBR- nitrile butadiene rubber.....NO

SBR- styrene butadiene rubber....NO

PU- polyurethane....NO

PA- polyacrylate rubber .....NO....one of the worst of the bunch.

PVC- polyvinyl chloride....YES....however PVC....mechanically....is crap. It has no place in a car. It slowly hardens up with age, cannot be clamped without crushing, kinks easily etc. Cheap and brake fluid proof...sure. But it's essentially only useful for your mity-vac and self bleeder set ups.

Neoprene-....YES...KIND OF. The mykin list gives it a "2"...which is fair. I just call it what it is....50%. It also begs the question of WHICH neoprene?
Neoprene starts out OK but gets gummy and starts to swell after a few months....depending on the formulation and how it was molded.

Silicone- ....YES....very good with brake fluid.....BUT....only useful for the feed line with "0" pressure and not really able to be clamped.
Keep in mind. If you can find and afford silicone.....you can far more easily find and afford EPDM.

Synthetic rubber?.....100% of those listed above are Synthetic.

Others not listed....Viton....terrible with DOT 3/4 brake fluid. HBNR or HSN....NO....bad with brake fluid.

Nylon....YES. very good with brake fluid if you can get it to connect up!

A very crude approximation.....if a rubber whose name/chemistry you do not recognize says its good with mineral oils and solvents....like paint thinner, xylene, gasoline etc.....it generally is poor for brake fluid.

Also....a lot of bad or old information out there. A really good bunch of people are the people at Apple Rubber. However, if you Google "what rubber works with brake fluid....it pops up "Ethylene propylene Rubber" ....from Apple Rubber.

This is not actually...exactly correct. EPR rubber is a different formulation than EPDM.
EPR rubber was used in the 1940s through part of the 1960s....and maybe into the very early 1970s in Europe.....when brake fluids were mineral oil based.

You could say these earlier brake fluids were somewhere in between mineral and glycol based. The EPR rubber worked excellent with mineral fluids.

However, when fluids changed to glycol based.....the EPR only worked....OK. It had a shorter lifespan than is acceptable with automotive brake products. The rubber was reformulated into EPDM.
EPR = ethylene propylene rubber
EPDM = ethylene propylene diene monomer.

EPR= only about 50% with DOT 3/4
Likewise
EPDM = only about 50% with mineral based brake fluid.

Be careful when you are speaking to someon at a rubber shop and he says the rubber is ethylene propylene....and then you ask...."so it's EPDM?"....and he says....yeah same thing. NO! Make them show you a data sheet from the manufacturer!

Not the same thing.

The only safe rubber for tubing and hose products for brake fluid is EPDM. Ray

Mon Jan 15, 2024 10:34 am

aeromech wrote: Send a link Ray and I’ll let you off the hook

Damn...can't believe I forgot to get aeromech a link 3 years ago ! :roll: :oops:

Check this out from Mcmaster Carr. I have used this hose with brake fluid with no issues.

A lot of times people skip over this heading in the MC catalog (me too) because they are looking specifically for EPDM and instead of saying what hose is under the tab they are listing it as UV resistant hose.

EPDM also just happens to be very UV resistant which is why its used for windshield and window gaskets. Which is also why you should not be using any solvent products on your windshield gaskets...like WD-40 or Vaseline petroleum jelly which is very bad for EPDM window gaskets.

https://www.mcmaster.com/products/tubing/uv-resist.../?s=tubing

Ray

Mon Jan 15, 2024 11:44 am

great info, cheers for that!

edit - i also found that a lot of high pressure air/gas hoses are suitable, or even ones for water. something you'd likely never think of looking for but are all strong, often industrial quality, EPDM hoses.