Remaking AC hoses right 3.5liter

[werminghausen]

I have to renovate my AC here in Oman on my 1971 300SEL 3.5. I have never had AC hoses redone and therefore I need some information what is technical standard, what is possible and what not.
I have Rotalock valves and all hose connections are without o-rings in my car.
I would wish to keep all the current fittings and just replace the hoses which are leaking.
I counted 5 hoses
1) from compressor to Rotalock.
2) from Rotalock to condenser
3) from condenser/drier to evaporator
4) from evaporator back to second Rotalock
5) from Rotalock back to compresspor.
see some of the fitting in the attached pictures.
Is it common practice to reuse all the old fittings?
Martin

[thorsen]

Are you planning on using barrier hose?
It is possible to re-use fittings but I avoid it when possible. Looking at the pictures it might not be possible to re-use that type.

[werminghausen]

Originally Posted by thorsen

Are you planning on using barrier hose?
It is possible to re-use fittings but I avoid it when possible. Looking at the pictures it might not be possible to re-use that type.

Thanks for responding,
I have no experience with remaking AC hoses.
Why are you saying you do avoid using old fittings?

Best would be if it were possible to redo hoses with the old fittings but I have no experience. I am in Muscat Oman, not in the US.
I'll look for a shop doing the hoses for me. However I do want to have some knowledge if it is a reasonable request to rebuild the hoses with the old fittings.
Martin

[Pooka]

I have been there and done that, so here is what I ran into.

First is the cost. If you are trying to save money then reuse everything. It can be done if you are careful. If you can remove the fittings without tearing them up then the hard part is over. Just be sure to line them up correctly when installing them again as they are easy to cross thread due to the fine threads used on these fittings.

The danger you will run into is that after you are through your A/C system will be working great and your hoses will be old. Too much pressure and one of them will blow out, and the correct operating pressure might be too much for the old hoses.

You could likely find someone to make you new hoses since there is such a thriving oil business in Oman. If you get new hoses be sure to specify barrier hose for auto A/C as it has a plastic lining inside of it to contain R-134. If you are going to go back with the original R-12, which I would recommend if it is possible, then barrier hose would still be the way to go since you may want to switch to R-134 someday.

See if you can find a Gates dealer in your area. Gates is a brand name of hose and they make good ones.

You might also just walk into the service department of a Mercedes dealer and ask the service people what they use and where do they get their hoses?

Hopefully this will help a bit.

[JPMOSE]

I am hoping to find a source for making red hoses like the ones furnished with our cars (so far my hoses aren't leaking). I think the dealer hoses are now black.

[werminghausen]

Originally Posted by Pooka

I have been there and done that, so here is what I ran into.

First is the cost. If you are trying to save money then reuse everything. It can be done if you are careful. If you can remove the fittings without tearing them up then the hard part is over. Just be sure to line them up correctly when installing them again as they are easy to cross thread due to the fine threads used on these fittings.

The danger you will run into is that after you are through your A/C system will be working great and your hoses will be old. Too much pressure and one of them will blow out, and the correct operating pressure might be too much for the old hoses.

You could likely find someone to make you new hoses since there is such a thriving oil business in Oman. If you get new hoses be sure to specify barrier hose for auto A/C as it has a plastic lining inside of it to contain R-134. If you are going to go back with the original R-12, which I would recommend if it is possible, then barrier hose would still be the way to go since you may want to switch to R-134 someday.

See if you can find a Gates dealer in your area. Gates is a brand name of hose and they make good ones.

You might also just walk into the service department of a Mercedes dealer and ask the service people what they use and where do they get their hoses?

Hopefully this will help a bit.

Thanks Pooka,

it is true that here is some oil business going on and I hope to find a good way to renovate the AC hoses. I'll try and get Gates/barrier hose here.
However this seems to be another route than going with the old fittings and us the Aeriquip hoses? Aeroquip isn't the same thing as a barrier hose if I got this right?
it really depends what I can get here locally and I am going from there.
However if I could reman the hoses myself with aeroquip and the old fittings I'd rather prefer this and remake the hoses myself. Thus I could almost get the AC to the point where I just need the shop to fill the system.
Martin

[thorsen]

Originally Posted by werminghausen

Thanks for responding,
I have no experience with remaking AC hoses.
Why are you saying you do avoid using old fittings?

Best would be if it were possible to redo hoses with the old fittings but I have no experience. I am in Muscat Oman, not in the US.
I'll look for a shop doing the hoses for me. However I do want to have some knowledge if it is a reasonable request to rebuild the hoses with the old fittings.
Martin

I try to avoid reusing fittings because I worry about damage to the threads. Plus new fittings are not that expensive compared to other AC work. I have a crimp tool I bought off eBay for $75 and usually budget about $100 for new hose + fittings when I do AC work.

I agree with Pooka's advice on using barrier hose (aka R-134a hose) even if you are using R-12. I am not sure what parts availability is like where you are but I wish you the best of luck!

[68_280SE]

Those fittings are reusable and are called aeroquip fittings. The braided hose is still available but unfortunately only in black. You should be able to find the black braided aeroquip hose by searching on the net.

John

[werminghausen]

Originally Posted by thorsen

I try to avoid reusing fittings because I worry about damage to the threads. Plus new fittings are not that expensive compared to other AC work. I have a crimp tool I bought off eBay for $75 and usually budget about $100 for new hose + fittings when I do AC work.

I agree with Pooka's advice on using barrier hose (aka R-134a hose) even if you are using R-12. I am not sure what parts availability is like where you are but I wish you the best of luck!

I looked at the threads on the hoses I opened and they all seem to be fine.
Not sure about the worry with leaking metal to metal connections.
Martin

[bwostosh]

Martin, I need to do the same task, oil lines and A/C lines, just be careful on the disassembley of the hoses R/H and L/H fine threads, clean the metal and should be no problem with correct replacement size lines.

[68_280SE]

The original hose is aeroquip 1540 and you can buy new black braided hose here.

1540 Refrigerant Hose

And here is a good link showing how to assemble hoses using aeroquip fittings.

Aeroquip 1540 Assembly Instructions


Hope this info helps,
John

[werminghausen]

Originally Posted by 68_280SE

The original hose is aeroquip 1540 and you can buy new black braided hose here.

1540 Refrigerant Hose

And here is a good link showing how to assemble hoses using aeroquip fittings.

Aeroquip 1540 Assembly Instructions


Hope this info helps,
John

John,
this is great information....
Does it mean that new aeroquip 1540 hoses and the old fittings can be assembled without any crimping tools?
If yes I just need to find the right type of hoses here in Oman.
I'll try and figure out the hose sizes I'll need.
Martin