'72 FLH front forks
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Road Master
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'72 FLH front forks
New to me '72 FLH. When riding over a speed bump or the like, forks bottom out when unweighting in the upward direction. I went to change the fork oil and very little maybe a couple of ounces came out of the left tube and about 5 ounces out of the right. I disassembled the nacelle and went to fill the tubes as normal. It was then I discovered when oil overflowed immediately that there is no hole in the tube plug. I have a manual ordered for '72-'78 but it hasn't arrived yet. How are you supposed to fill the tubes? I read some old threads and filled them through the drain plugs with an oil can but the problem still persists. What do you think the problem is and how are you supposed to fill with oil?
Thanks in advance.
Thanks in advance.
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From: la la land jerzey
I would spend the time and take them all apart and clean and re seal the forks - then use 30W lawn mower engine oil in the forks - forget what the book says
been doing it that way 30 plus years you will not be disappointed
been doing it that way 30 plus years you will not be disappointed
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Road Master
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Thanks John. I always appreciate your input. Sounds like a winter project as we still have some decent riding weather until the snow flies. Any thoughts on why there are no fill holes in the tube plugs?
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From: la la land jerzey
they are plugged with debris when doing that they usually end up blowing the seals out and your real down on fluid so its been going on
the top caps have side vent holes in them -- look
the top caps have side vent holes in them -- look
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Road Master
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At the risk of seeming slow, I see that the top caps have vent holes but I probed around with a sharp awl and couldn't find the holes in the plugs to fill through. Are all years the same? Thanks again.
Cruiser
Joined: Jun 2014
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From: Minnesota
This sounds like the same issue I ran into with my '72 FLH in the spring. Everyone said there was supposed to be a spring under the fill caps at the top of the forks, but all I saw were what looked to be a couple valves an inch or two below the top of the threads. No spring under the cap. And every time I poured oil, it would overflow, it would not flow down through the valves.
I ended up taking a plastic transmission funnel, sealing the end of it into the threads of the fill hole, poured the correct amount of fork oil into the funnel, and then had to slowly pump the forks up and down. That sucked the oil down and filled the forks.
It sounds like the internals of the front end changed around the mid '70s, but I'll know for sure when I tear into my dad's '77.
I ended up taking a plastic transmission funnel, sealing the end of it into the threads of the fill hole, poured the correct amount of fork oil into the funnel, and then had to slowly pump the forks up and down. That sucked the oil down and filled the forks.
It sounds like the internals of the front end changed around the mid '70s, but I'll know for sure when I tear into my dad's '77.
Club Member
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From: Niles Canyon Ca.
Caps have to come off you can't fill through the 1/2" holes it would take you a week if you tried and no all year are not the same, you need the parts break down for your year bike. There where several changes in later years and they didn't interchange. Also be careful to not over fill or she'll pump oil mist out the vent holes, get's messy with a nacelle.
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From: la la land jerzey
scrub everything clean and follow the book and its not that bad to do
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Road Master
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Thanks John, Twizted, and 72 for your replies. As stated earlier, service manual on the way. Forks must have changed after '70 because the other Shovels fill through the top plugs. Doesn't make sense that it would be designed that you would have to disassemble to change the oil. I figured there must be a special tool to remove the top plugs the way it is designed. Any thoughts on where to get one? I will follow John's advice and tear it down and clean it up this winter as there is definitely more working here than that it was just low on oil. Any recommendations for a rebuild kit or if not, specific parts that should be replaced? Thanks again for all your help.
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From: Santa Klaus County, Cali
This is the tool I use in order to safely remove the fork tube plug. It is is Trock tool that is now manufactured by Burgs Bike Tool Co. out of Aurora Il. Herz a phone number on them 847-772-2283. I do not recall where i got mine from but I know it didn't cose me a C-note at the time. i am sure other places carry this.
http://www.retrocycle.com/CustomChro...ompressor.html
And re: adding oil to the tubes once assembled. There is a hole in the fork tube plug that is accessed once you remove the cap. The service manual for panhead shows an elaborate drip system to add oil because the hole is definitely small. My 49 is an early front end and doesn't have the baffle system that was added to the bottom of the fork tube plugs that was used for later hydraulic fork front ends, so undoing the caps gives me a straight access to add oil w/o restriction; my 65 obviously does. For that I simply use a plastic syringe. Even with the syringe it takes some time because it is an enclosed system and the only air vent is the hole you are adding the oil through.
And remember that once you take it apart and clean it, it will be considered dry so the amount added will be more.
And if you get really ambitious, start a thread with pics on the disassembly, cleaning and reassembly process. Winter's coming right so we will all have a lot of extra time
http://www.retrocycle.com/CustomChro...ompressor.html
And re: adding oil to the tubes once assembled. There is a hole in the fork tube plug that is accessed once you remove the cap. The service manual for panhead shows an elaborate drip system to add oil because the hole is definitely small. My 49 is an early front end and doesn't have the baffle system that was added to the bottom of the fork tube plugs that was used for later hydraulic fork front ends, so undoing the caps gives me a straight access to add oil w/o restriction; my 65 obviously does. For that I simply use a plastic syringe. Even with the syringe it takes some time because it is an enclosed system and the only air vent is the hole you are adding the oil through.
And remember that once you take it apart and clean it, it will be considered dry so the amount added will be more.
And if you get really ambitious, start a thread with pics on the disassembly, cleaning and reassembly process. Winter's coming right so we will all have a lot of extra time
Last edited by panz4ever; Oct 1, 2017 at 10:32 AM.