Remaking AC hoses right 3.5liter

[werminghausen]

I measured the Outer Diameter (OD) of the existing old airoquip hoses in my car:

1) compressor- Rotalock 1 OD = 25mm

2) Rotalock 1 - condenser OD = 20mm

3) Drier- evaporator OD = 17.5 - 18mm

4) evaporator- Rotalock 2 OD= 25mm

5) Rotalock2- compressor OD= 25mm



On the 1540 Aeroquip website
1540 Refrigerant Hose

I can find Outer Diameters
#6 = 0.67"= 17.018mm
#8 = 0.75" = 19.05mm
# 10 = 0.92" = 23.4mm
# 12 = 1.06" = 26,94mm

Now comes the question:

What size hose should I order?
I seem to have 3 different size hoses but
the OD numbers don't quite fit.

Martin

[werminghausen]

I read on a Ferrari Forum, that the old Ferrars used #6, #8 and #10 aeroquip 1540 hose
www.tomyang.net • View topic - Replace Old A/C Hoses

There is a good chance that Mercedes used the same hose sizes.

Comparing the existing Outer Diameter with the new ODs of the #6, #8 and #10 aeroquip 1540 hose the new hoses are slightly smaller than the old ones.
If they were originally the same how can this be? can hoses grow in Diameter?

I mean do the #6, #8 and #10 aeroquip 1540 hoses fit?

#6: old OD 17.5mm new OD 17.02mm (0.67") Difference 0.5mm
#8: old OD 20mm new OD 19.05mm (0.75") Difference 1mm
#10: old OD 25mm new OD 23.4mm (0.92") Difference 1.5mm

OD = Outer Diameter of the braided hose

Does anyone have experiences here? Before I order I would love to have some feedback. Thanks, Martin

[werminghausen]

I contacted Dunham Rubber

I figured I'd need around the following lengths:

4 feet of #6, (1 hose drier - evaporator)
3 feet of #8 and (1 hose, 1'-2" length, compressor- Rotalock plus 1 hose Rotalock -condenser ,1'-8" length)
5 feet of #10 (1 hose evaporator- Rotalock, 4'-2" length plus 1 hose, Rotalock- Compressor, 10" length)

They sell 1540 hose (this one is for R12 only)
1540-6 $15.08 PER FOOT
1540-8 $16.18 PER FOOT
1540-10 $17.97 PER FOOT


As an alternative they sell FC802 hose (for both R12 and R134a)
FC802-06 $5.77 PER FOOT
FC802-08 $6.52 PER FOOT
FC802-10 $8.12 PER FOOT
They have stopped making the 1540 hose and have a little in stock.The FC802 hose took its place it does not have a cloth cover it has a rubber cover both hoses will work with our fittings according Dunham Rubber.

What do you think? Any suggestions?

Martin

[werminghausen]

I measured today also the ferrule part hex diameter (see pictures showing
ferrule hex) and the corresponding ferrule pipe hex diameter.
#6: ferrule hex (female part) 23mm , ferrule pipe hex (male part) 17mm
#8: ferrule hex (female part) 25mm , ferrule pipe hex(male part ) 19mm
#10: ferrule hex (female part) 30mm , ferrule pipe hex (male part) 19mm


Can someone confirm that fittings and hose sizes correspond before I order?
Martin

[werminghausen]

I found this on a website
There is great information about the FC802 system

http://www.powerflex-fhp.nl/local/anniecms/1/images/EA78E_a-c.pdf


Hose FC802: Page 10

Fittings GA494/FC802: Page 49-51

How to install hose and reusable fittings: Page 70

It seems that the hose FC802 has a slightly higher OD than shown in the Dunham website: see page 10
#6 OD=17.6mm
#8 OD=20mm
#10 OD=24 mm

These diameters correspond better with my measured diameters of the old 1540 hose ...except for the 25mm of #10

I am pretty sure now that #6/8/10 is the correct size hose for our systems.

The aeroquip sizes correspond with the ND sizes (with is the Inner hose Diameter [ID]of the hoses in mm)
#6 = ND 8
#8 = ND 10
#10 = ND 13

[werminghausen]

I took the first hose size 6 from drier to evaporator apart.
After removing the hose from the car I unscrewed the ferrule pipe (right hand thread) on both ends which I could do by hand. Then I removed the ferrule itself which has a left hand thread. I'll attach pictures.
I noticed that there is a '6' marking on the hex of the ferrule. So I am sure now about the size.

Martin

[werminghausen]

I removed the condenser and the short hose from Rotalock to condenser yesterday. It is a 30cm (12") long #8 hose. Easy removal of aeroquip fittings.
It is good to spray some WD 40 into the gap between ferrule and hose before removal.

[werminghausen]

update: I have remove all AC hoses, compressor and condenser now. fittings are removed and ready for cleaning.
I am ordering FC802 hoses soon

Lenths of hoses FC802:
hose no. 1 , compressor- Rotalock1 1'-5" (0.425m precisely) size 8
hose No.2 Rotalock 1-condenser ,1'-0” (0.30m precisely) size 8
hose No.3 drier – evaporator , 5’-0” (1.50m precisely) size 6

hose No.4 evaporator- Rotalock2, 4’-0” (1.20m precisely) size 10
hoseNo.5 , Rotalock2- Compressor, 11" (0.27m precisely) size 10

There was quite some AC oil in the condenser and hoses.

[werminghausen]

update: I have bought the black rubber hoses from aeroquip (not the original ones) and installed the fittings. They look nice.
I have removed the evaporator and I am waiting for the cone seal washers for the reinstall.
Martin

[werminghausen]

I have all parts now together and I am about to reassemble the hoses.
One detail I didn't realize at the beginning. These are the cone seal washers in all the SAE 45 flare connections. Here is a list of seal washers you'll need.
I'll start another threat for the assembly of the AC components

[Peterac]

Great info, please continue with info. I will do the same job as I can see ends of my hoses dirty from weeping oil/gas over time. Your write up has given me confidence to try this job! Thankyou.

[werminghausen]

Originally Posted by Peterac

Great info, please continue with info. I will do the same job as I can see ends of my hoses dirty from weeping oil/gas over time. Your write up has given me confidence to try this job! Thankyou.

Thanks,
well this is the end of story. I forgot to get a very small cone seal for the new expansion valve line (it is a cone with 10mm OD and 5mm ID) but all the rest worked out great. My AC is blowing ice cold now.
As I mentioned before the evaporator and installation of compressor without a lift are a drag. But in the end it is worth while.
Martin