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Brake Lines and Fittings - Updated Specs & PNs?

LouFly

Well Known Member
While waiting on our prop overhaul have decided to take a hammer to the brake fluid leaks and sponginess on the pax side and parking brake of our -6A. After 20 yrs and 2000 hrs I guess a little maintenance is not unreasonable. Lots of good info here on VAF, via Matco (thanks George Happ) and also on Kitplanes (subscription worth it) has a good article Feb'18 about overhauling the Matcos and a good example May'20 of the jam nut/stud mount for those of us who can't use the 'long bolt' mod.

Matco had a good point about the locking collars and external spring. You can add that collar with the idea that the scoring is beyond the normal throw but they point out: "it will damage the seal at overhaul" when you slip it all back together.

Pleasantly surprised (so far) that the overhaul of the Matco cylinders is not too bad. I saw a lot of references here to add external springs which George Happ recommended against. Interestingly the replacement springs (in the overhaul kit were longer).

I've decided to keep the Vans design - plastic tubing for the low pressure parts of the system. My question: is that it seems a lot of the part numbers of the components (tubing, compression fittings, ferrules) have been updated over the years with more nylon/acetal components being used. I'm finding it difficult to just punch my plans part numbers into Vans Store or ACS to get the right fittings. Do the plans for the newer RV models spell these out? I was starting the hunting/pecking process but a good BOM would save some time.
 

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While waiting on our prop overhaul have decided to take a hammer to the brake fluid leaks and sponginess on the pax side and parking brake of our -6A. After 20 yrs and 2000 hrs I guess a little maintenance is not unreasonable. Lots of good info here on VAF, via Matco (thanks George Happ) and also on Kitplanes (subscription worth it) has a good article Feb'18 about overhauling the Matcos and a good example May'20 of the jam nut/stud mount for those of us who can't use the 'long bolt' mod.

Matco had a good point about the locking collars and external spring. You can add that collar with the idea that the scoring is beyond the normal throw but they point out: "it will damage the seal at overhaul" when you slip it all back together.

Pleasantly surprised (so far) that the overhaul of the Matco cylinders is not too bad. I saw a lot of references here to add external springs which George Happ recommended against. Interestingly the replacement springs (in the overhaul kit were longer).

I've decided to keep the Vans design - plastic tubing for the low pressure parts of the system. My question: is that it seems a lot of the part numbers of the components (tubing, compression fittings, ferrules) have been updated over the years with more nylon/acetal components being used. I'm finding it difficult to just punch my plans part numbers into Vans Store or ACS to get the right fittings. Do the plans for the newer RV models spell these out? I was starting the hunting/pecking process but a good BOM would save some time.

FYI, the lines that go between the co pilot and pilot brakes are HIGH pressure, not LOW (at least when the co pilot is braking). Be sure to use the stronger parker lines and not nylon for these.

Larry
 
FYI, the lines that go between the co pilot and pilot brakes are HIGH pressure, not LOW (at least when the co pilot is braking). Be sure to use the stronger parker lines and not nylon for these.

Larry

Thanks Larry noticed that. My thought was just to use the better ones all around. Not much diff in weight or $. Trying to reconcile:
1. Plans: "SN" vs. "NSR"
2. Vans Store: Parker "N" Nylon .064 wall vs. Parker "N" .035 vs...
3. ACS: Nylaflow vs. Nyloseal (N - .035 or NSR-.050).

ACS says Poly Flow fittings with "N" but SAE fittings with "NSR"

I'm sure I'm overthinking, but it's really a lot of time under the panel pulling this stuff all apart and will be to put back together.
 
Man -- we checked this just before this SB was updated. Looks like Vans is backordered on the parts, bummer.

Just pull the pedals out and take them to a local welder. Let him know it is 4130 steel and show him a picture of the gusset from the SB. You could buy the 4130 from Mcmaster and make the gusset yourself to save a few buck. Only need a cut off tool and die grinder. You can ask van's, but suspect the gusset is 1/16" but could be an 1/8".

I think the weldments are one of the worst delays and could take over a year to get one.

Larry
 
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