Old M39 M809 series: brake and air lines identical?

Steel Soldiers is supported by:

Robo McDuff

In memorial Ron - 73M819
Steel Soldiers Supporter
2,441
191
63
Location
Czech Republic
I was looking at one of the scrapyards for my missing fixed brake line. Found something I thought would fit, then noticed it actually was an air line. Were they the same in strength and diameter?
The line I am looking for is 0.39 inch (10 mm), from the slave cylinder to the distribution point.
 

162tcat

Member
676
7
18
Location
Washington
Air line and brake line aren’t interchangeable! Air is likely copper which would rupture as brake line. Head to the auto parts store to buy steel brake line and rent the flairing tool while you’re there.


Sent from my iPhone using Tapatalk
 

Robo McDuff

In memorial Ron - 73M819
Steel Soldiers Supporter
2,441
191
63
Location
Czech Republic
The problem is, I am living in the Czech Republic. All the brake lines available here - or in most of Europe - are either 8 mm (all person cars) or 12 mm for larger vans. I can get 10 mm from one of the Dutch scrapyards, but only as a roll of 50 m ($$$), while I only need 50 cm.

Are copper lines not strong enough? One option I was considering was to use 10 mm copper gas line if I could not find anything else.
 

Robo McDuff

In memorial Ron - 73M819
Steel Soldiers Supporter
2,441
191
63
Location
Czech Republic
I was buying some things to repair the air system, and came across a 50 cm hydraulic flex line suitable for a working pressure of 150 bar (2200 psi) and a burst pressure of 200 bar.

With a connector added on each side, I can make it fit the connector at the front of the slave brake cylinder at the airpack and the 3-way connector on the frame splitting the brake line to front and back. Not ideal, but for the moment with only slow local driving on our own yard it will hopefully work.
 

fasttruck

Well-known member
1,000
125
63
Location
Mesa, AZ
Remember with an air system the first several feet on he discharge side of the pump must be metal or metallic so it does not melt from the hot air being discharged from the pump. A plastic line up to the pump will fail.
 

Robo McDuff

In memorial Ron - 73M819
Steel Soldiers Supporter
2,441
191
63
Location
Czech Republic
Thanks for the heads-up. I will use modern plastic air hoses only the last part of the way to the glad-hands.

The hydraulic hose I will use as replacement for the brake line between the end of the slave cylinder in front of the airpack to the split-connector on the frame, about 20 inch away, mostly upward. So heat should not be a big problem, certainly because this truck is mnot going to be used on normal road, only forest roads to carry concrete and stone debris to fill a ditch.
 

NY Tom

Member
Steel Soldiers Supporter
90
12
8
Location
Riverhead, NY
This stuff is good and made in England. Not sure if you can get that in Czech Republic though. Cunifer tubing. It is sold in English and Metric diameters.


Here is a USA distributor website if it helps.


Tom
 

Robo McDuff

In memorial Ron - 73M819
Steel Soldiers Supporter
2,441
191
63
Location
Czech Republic
Thanks. My problem is that this section of brake line has a 10 mm tube. I can get 8 and 12 here, but not brake-line quality 10 mm. I don't want to use the much smaller 8 mm, and the 12 mm I cannot fit in the connectors.
 

NY Tom

Member
Steel Soldiers Supporter
90
12
8
Location
Riverhead, NY
I tried to link to the 10mm section of that website. The size you need is available just not sure how easy it will be to get it to you.
 

Robo McDuff

In memorial Ron - 73M819
Steel Soldiers Supporter
2,441
191
63
Location
Czech Republic
Thanks a lot for the link. Problem is that this does not count as document, so quick transport is crazy expensive, slow mail still $$ enough. Let's see how the hydraulic line holds up for now.
 
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks