Harvard Mk.4 hoses
Thu Mar 15, 2012 7:58 pm
We are gearing up to replace all the hoses in the engine compartment on our Harvard.
Either we buy the stock hoses and rebuild them ourselves or we ship them to a facility where they take care of it.
Does anyone specializes in these hoses?
Either we buy the stock hoses and rebuild them ourselves or we ship them to a facility where they take care of it.
Does anyone specializes in these hoses?
Re: Harvard Mk.4 hoses
Fri Mar 16, 2012 7:09 am
Which Hoses?
Flex Lines with ends that connect to AN fittings?
Solid Alum Tubes with short rubber hoses with hose clamps?
If it is the flex lines they can be done in house. You need to follow info from the maker. Their are 2, Stratoflex and Aeroquip. They meet a Mil-Spec and are the standard for that type of hose assemblies.
The ends can be reused but many times the alum collar can have the affects of corrosion internally where the fabric of the hose touches the ID of the collar.
They need to be tested by applying pressure before use. Special mandrels are required as well for assembling the ends to the hose.
If you don't have the experience and tools then a hose shop or local maint facility with experience and willingness is the best bet.
My local one in this area is Eastern Aero Supply, 1001 N 10th St Millville, NJ. Phone: 856- 327-8949.
I'm sure someone has a shop closer.
Flex Lines with ends that connect to AN fittings?
Solid Alum Tubes with short rubber hoses with hose clamps?
If it is the flex lines they can be done in house. You need to follow info from the maker. Their are 2, Stratoflex and Aeroquip. They meet a Mil-Spec and are the standard for that type of hose assemblies.
The ends can be reused but many times the alum collar can have the affects of corrosion internally where the fabric of the hose touches the ID of the collar.
They need to be tested by applying pressure before use. Special mandrels are required as well for assembling the ends to the hose.
If you don't have the experience and tools then a hose shop or local maint facility with experience and willingness is the best bet.
My local one in this area is Eastern Aero Supply, 1001 N 10th St Millville, NJ. Phone: 856- 327-8949.
I'm sure someone has a shop closer.
Re: Harvard Mk.4 hoses
Fri Mar 16, 2012 7:19 am
Cheers,
We have the equipment and skills do them in house, we are still at the planning stage so I'm gathering infos.
Solid lines appear to be OK, but we'll know better when we remove everything. Flexible lines have to go for sure.
My mechanic is jumping all around the place talking about Teflon hoses. Are they really that good?
We have the equipment and skills do them in house, we are still at the planning stage so I'm gathering infos.
Solid lines appear to be OK, but we'll know better when we remove everything. Flexible lines have to go for sure.
My mechanic is jumping all around the place talking about Teflon hoses. Are they really that good?
Re: Harvard Mk.4 hoses
Fri Mar 16, 2012 8:45 am
Teflon lined hoses have their place, but they are easy to damage internally. If you ever kink or crush one, it's trash and has to be replaced. The hose will still hold pressure, but the area that has been damaged will no longer retain the original cross section so you will have localized flow problems. We use a bunch of teflon lined, stainless braided hoses at work on our a/c and they freak when we have to change one due to damage. So in my book, if you have a specific need for them, use them, but remeber their low tolerence for mishandling.
Re: Harvard Mk.4 hoses
Fri Mar 16, 2012 12:55 pm
Cheers for that!
Re: Harvard Mk.4 hoses
Fri Mar 16, 2012 3:50 pm
Ollie wrote:Cheers,
We have the equipment and skills do them in house, we are still at the planning stage so I'm gathering infos.
Solid lines appear to be OK, but we'll know better when we remove everything. Flexible lines have to go for sure.
My mechanic is jumping all around the place talking about Teflon hoses. Are they really that good?
The medium pressure hoses have worked well for 60 years. They are easy to maintain and fit in as far as period appearance. Unless you need to do otherwise I'd stay with them.