Flap pump bleed valve plastic seat

[Mark Van Der Hart]

Has anyone found a part # for the plastic ball seat (#23 in some exploded views) inside the HE-626 flap pump assembly?

Flap Pump parts.pdf

[47U]

In infamous HE-1677 (I think).  Have you tried the used parts places?  Or, Dan at LASAR?  

Someone with some skills could make one, too… if you have the old one for dimensions.

[Shadrach]

9 hours ago, Mark Van Der Hart said:

Has anyone found a part # for the plastic ball seat (#23 in some exploded views) inside the HE-626 flap pump assembly?

Flap Pump parts.pdf 853.35 kB · 6 downloads

Have you lost yours or is it leaking? I’ve had good luck getting them to seal by staking the ball against the seat.

[Mark Van Der Hart]

I'm overhauling my pump due to a sticking check balls (the 5606 fluid got old...).  Someone overhauled it back in the 80's and gouged this ball seat when they were changing the o-ring around it.  It's a miracle that it sealed all these years.  I did find a part # in a later Mooney parts manual ('66 and after).  The part # is HE-1677.  I'm hunting for one, but I'll make it if I can't find one.  It's TFE of PTFE, OD is .3335", ID is .1315", thickness is .0685".

[Mark Van Der Hart]

Here's the exploded view.

Hydraulic System Parts.pdf

[Shadrach]

1 hour ago, Mark Van Der Hart said:

Here's the exploded view.

Hydraulic System Parts.pdf 531.01 kB · 0 downloads

Yes, everyone who has replied to this thread is familiar with this part. It is not a miracle that it sealed, indeed it is quite typical for seals that look questionable to seal just fine…especially if you gently stake the ball against the seat as I mentioned previously. You may also flip the seat over and use the other side.

These parts are no longer in production so if you are unable to make yours work you would need to go the owner produced route. 

 

[Mark Van Der Hart]

Thanks Ross.  I'll make a new one and report back.  This one is seriously damaged, and I won't re-install it.

[N201MKTurbo]

53 minutes ago, Mark Van Der Hart said:

Thanks Ross.  I'll make a new one and report back.  This one is seriously damaged, and I won't re-install it.

I seem to recall they were made out of PTFE, those look like PE. Perhaps those are already home made.

[Shadrach]

1 hour ago, Mark Van Der Hart said:

Thanks Ross.  I'll make a new one and report back.  This one is seriously damaged, and I won't re-install it.

That one looks homemade to me. I have a spare pump with intact seals if you want to put eyes on it. I have a hard time believing that a credentialed mechanic did that to a seal. I’ve seen some poorly done mx but that takes ham fisted to a new level.

[Mark Van Der Hart]

I agree, but I've been in technical repairs for over 40 years, and I've seen some shoddy repairs by supposed credentialed repair persons.  This was factory overhauled by HE in OK City.  Still had the sticker on it.

Ya know, it all depends on the character of the person doing it... whether they really give a rip or not.

 

Before you open one up, let me see how it goes on making a few of these on the lathe.

Thanks very much.

Mark

[A64Pilot]

Don’t use 5606, as you know it turns to goo, use 83282 Military changed to it ages ago, it’s for resistant and fully compatible with 5606

https://www.csobeech.com/5606-Replacement.html

[Mark Van Der Hart]

Thanks!  Ordered some.  Far rather use synthetic than straight mineral based.

[Shadrach]

47 minutes ago, A64Pilot said:

Don’t use 5606, as you know it turns to goo, use 83282 Military changed to it ages ago, it’s for resistant and fully compatible with 5606

https://www.csobeech.com/5606-Replacement.html

I'm trying to find a document that authorizes its use as a drop in substitute.  Can you point me to something other than that CSO Beech post?

[Mark Van Der Hart]

Update on progress...  I machined a new seat out of .375" PTFE rod.

1. Center drilled it.

2. Faced the end.

3. Chamfered the hole.

4. Turned diameter to spec.

5. Cut off.

6. Micro-cleaned it with an exactoknife under the lighted magnifier.

[EricJ]

That's a fine example of some good OPP right there.

 

[hammdo]

I’ll take 2 ;o) excellent work!

-Don

[Shadrach]

Well done Mark! I don’t think the originals were chamfered. They just look that way after years of use.
Still a good idea to lightly stake the ball to the seat.

[Mark Van Der Hart]

I had to buy 36" of the rod.  I'm going to see how many of them I can make in two hours.

[Mark Van Der Hart]

The seat went in nicely, and the o-ring nested around it good.  The kit was from Lasar, and included the o-ring.

I have the pump together, and I bench tested it enough to make sure that it seals and releases.  I installed it back on my plane but it'll be several days before I have time to fill and bleed the system and test it that way, as well as set the bleed-off rate.

[hammdo]

Very nice!

-Don

[Shadrach]

 

24 minutes ago, Mark Van Der Hart said:

The seat went in nicely, and the o-ring nested around it good.  The kit was from Lasar, and included the o-ring.

I have the pump together, and I bench tested it enough to make sure that it seals and releases.  I installed it back on my plane but it'll be several days before I have time to fill and bleed the system and test it that way, as well as set the bleed-off rate.

Did you add a PTFE valve seat to the return circuit?  That circuit has a seat machined into the pump body.  The o-ring should mount on the set screw below the jam nut. 

[Mark Van Der Hart]

I didn't add, I replaced.  It had the PTFE seat and o-ring in it already.  Some diagrams (like the one you attached) don't show it and that threw me a loop for a while.  But in the 1966 parts breakdown it is shown (my previous attachment, and here again partially).

This pump was overhauled by HE in the early 80's, and I can only assume that they did it then since there's no log record of it being done again since then, and their overhaul sticker was still on the pump.

Before my 5606 fluid gooed up, this worked very well since they overhauled it, so I chose to go back exactly the way it was, except with a non-damaged seat.

The o-ring that you referred to is there (AN6290-5) but this uses a different o-ring to seal around the PTFE seat (AN6227B-8 or MS28775-011).

Mark

[Mark Van Der Hart]

Correction to a typo in my last post...

That o-ring part # is AN227B-6 NOT AN227B-8.

And here's a snapshot of the later parts book.

Mark

HE-1677 Washer.pdf

[Shadrach]

1 hour ago, Mark Van Der Hart said:

I didn't add, I replaced.  It had the PTFE seat and o-ring in it already.  Some diagrams (like the one you attached) don't show it and that threw me a loop for a while.  But in the 1966 parts breakdown it is shown (my previous attachment, and here again partially).

This pump was overhauled by HE in the early 80's, and I can only assume that they did it then since there's no log record of it being done again since then, and their overhaul sticker was still on the pump.

Before my 5606 fluid gooed up, this worked very well since they overhauled it, so I chose to go back exactly the way it was, except with a non-damaged seat.

The o-ring that you referred to is there (AN6290-5) but this uses a different o-ring to seal around the PTFE seat (AN6227B-8 or MS28775-011).

Mark

Very interesting.  I have only taken apart about 10 pumps.  I have never seen one configured as you describe.  Indeed, mine would not function if configured as you describe.  The cam lift is just enough to unseat the ball from the machined aluminum seat.  The pin on mine would be too short to unseat the return circuit ball if configured like yours.

[Shadrach]

1 hour ago, Mark Van Der Hart said:

Correction to a typo in my last post...

That o-ring part # is AN227B-6 NOT AN227B-8.

And here's a snapshot of the later parts book.

Mark

HE-1677 Washer.pdf 21.29 kB · 2 downloads

My IPC calls for a washer as well.  This piece has been discussed many times because it is not typically present in the assembly.  Indeed, I have never seen one.  The o-ring in your diagram goes on the the threaded restrictor, not in the pump body.  As I said, non of the pumps that I have seen had the washer.  The that your substituting a PTFE seal for said for what is labeled a washer leads me to believe there will be a good probability of leak down through the retract circuit after reassembly. Whoever was in there last looks to have reinterpreted the drawing.  The seals you took out give an indication of how talented the rebuilder was.  They looked home made to me. Just because HE was the last person to touch it in the logs does not mean that reflects reality.

Ho fast did you flaps retract before you removed the pump? 10 secs on the ground is ideal.  The reason I ask is that you may get it to function as configured if you crank down on the restrictor but adjustability may be an issue. 

You seem confident and competent. I'm sure you'll manage. Good luck! I hope it does not become too adventurous...