View Full Version : Disk Brake upgrade for 1955 PA22-150

Glen Geller
03-31-2008, 10:18 PM
Hi Folks,
This has been addressed elswhere ad nauseum, but I hope I can get a definitive answer to the nagging question:
What is the best/easiest/surefire-sign-off/economical route to convert the original drum brakes to a more modern disk brake?
I think in addition to changing the brakes & wheels, I might also switch from the NRBB to the Steve's Master Cylinder (low-profile under the hood on my '55 PA22.)
Among the suggestions I have heard around the various water coolers are the Stinson 108 brakes from AC Spruce etc; Piper Cherokee; PA22-108 parts. Of course it is important to get them approved by the FSDO (we have a pretty good FSDO here at KHIO due to the great number of restorations and homebuilts in the region.)
And if the disks are installed does that mean stock Piper wheel pants will no longer fit (or will possibly fit with some modification?)
I have a very good A&P who knows his way around fabric Pipers for 50 years, but we wanted a consensus from the online gang to help avoid pitfalls.
What do you folks with disk brakes on your PA22's suggest? Spare no details please!

04-01-2008, 11:28 AM
Glen, I have the paperwork for installing disc brakes on a PA 22 135, 150, 160 It's the Williams STC paperwork with 3 pages of prints and details for which parts to use.It calls for parts off of Cessnas or Cherokees. I would like $50.00 for the paperwork. I used Cessna 150 master Cylinders on my exp. and the Disc brakes off the Williams STC . They work super, however I am sure you can't use your wheelpants without modifing them. Thanks Sam

Steve Pierce
04-01-2008, 12:23 PM
The Williams STC SA09150SC uses a wheel assembly 40-86 and brake assembly 30-55. I'm not sure what that is off of. Johnny sold most of his stuff to someone in Canada who advertises in the SWPC News. He might can help. According to the Type Certificate Data Sheet the disc brakes are only approved on the PA22-108. They are a 40-28 wheel assembly and I think I have a spare set of the wheel and brake combination. Univair has an STC SA91AL to replace the drum brakes on a PA22-150-160-135 with the PA22-108 wheels and disc brakes. I searched the STC data base and those are the only two STCs I could find. I have gotten and seen field approvals but we all know that can be easy or impossible depending on your own FSDO. Bodell brakes I thought were STC'd and you wouldn't have to cut the wheel pants.

04-01-2008, 07:03 PM
I got a Field Approval, once, to install PA24-250 wheels and brakes on a PA22-160. But that was in the late 1980's. The Colt's gross weight is lower than the PA22 so I doubt FSDO would approve them. The Comanche brakes worked very well on the Tri-Pacer.

A good place to start is by calling Cleveland 1-800-BRAKING (Bra King)

Univair has an STC for disc brakes...that would be a lot easier than a field approval.

Indy, IN

04-02-2008, 11:12 AM
I installed the "Stinson" brakes and a Steve's Aircraft brake booster on my PA-22. I opted for the Stinson kit since it was quite a bit cheaper than the components used on the Colt. I obtained a field approval for the installation. The Stinson kit fit perfectly. Univair was very helpful and supplied me with the correct spacer and bolts to make the installation. As for the wheel pants I don't care for them, but I can see that considerable modification would be required to fit them to the Cleveland Brakes.


Glen Geller
04-03-2008, 01:08 AM
Well thanks all, I think I agree with Paul, and it turns out my hangar-mate did the Univair/Stinson version (~$1014 for brakes/wheels/hdwr and $400 for Steve's Booster) and he sent me copies of the 337s and all the other stuff.
I'll be visiting my local FSDO shortly with all this paperwork and ask if they will approve it again: same FSDO office, same airport, same mechanic, identical plane! I am cautiously optimistic they will give me the green light to go ahead.
Next week will be big OT at work and that should finance the bulk of the expense.
Thanks again and don't be shy if you have more advice about this, I really appreciate it.

Larry Huntley
04-03-2008, 08:05 PM
I used clevelands on my PA 22-160 many years ago. Called Cleveland ,told them what I wanted to do. Told them I did not want to buy new equipment. They said they didn't care and sent me all the paperwork for the whole assembly,blueprints and all. They are very helpful ,friendly people. I think my brakes came off an Arrow,can't remember. Still using the scott cylinder under the seat. I can skid the tires most anytime if I am not careful. Larry Huntley