Before disassembling your Gascolator, understand that there are three different units in original service. They all require a different set of gaskets or o-rings. The two earlier Gascolators were superseded by the later (third) unit. This latest unit was used to replace the first two types by means of the kit that I have previously mentioned. The two earlier types use a center bolt that clamps the parts stack together, with an off-center drain valve. The latest type has the drain valve mounted in the center of the special stack retaining nut.

The oldest unit is PNHE759-3, used through M1503, MA368, MB634, and MC205. This unit uses seals/gaskets; no o-rings.

The mid-production unit is PN 5059-3, used through M1859, MB812, and MC478. This unit uses o-rings for sealing. Unfortunately I know of no way to differentiate this unit from its predecessor, by looking at the outside. Since the internal machining in the body parts differs between the two models, the earlier model cannot just have o-rings substituted for the flat-style seals; it will probably leak.

The newest unit is PN A1540-4. It is also furnished in kit # 23-9026-1, used to mount the A1540-4 onall earlier planes. This unit also uses o-rings for sealing; they are not the same rings used on the prior model.

This variety of models and seals is the primary reason why I have not yet developed Gascolator o-ring kits. A secondary reason is that I have been unable to obtain photos of the two earlier models while they aredisassembled, in order to develop illustrated written instructions. If anyone can send me pix, I would appreciate it.

As an aside, all three of these Gascolators (fuel strainers) use a flat screen separator that is captured in the head of the unit. If improperly installed or damaged, it won't stop all the water (should any get in there). Fuel enters the bowl below the screen. Any water or debris cannot pass the very fine-mesh screen, and gets drained out during sumping. There is no indication in the parts book that tubular screens were used in any of these units. That doesn't mean that none ever were; and it is also possible that someone "enhanced" their Gascolator at some point in time (or installed some other unit).

And to sum up, other than the gaskets, o-rings, and Stat-o-seals, I know of no source for parts for any of these units, other than salvage yards. Salvage prices will probably climb over time, as RAPID now posts a price on these that exceeds $17,000 (not a misprint). Of course they have none, which is just as well as they'll never sell one at that price.

From: LtCol Rayford Brown (
Sent: Friday, July 15, 2005 12:39 PM

The gascolator is simple. Remove the safety wire from the nut on the bottom. That is what holds the top, bolted to the airplane, the cylinder wall, and bottom plate together. There are O-rings at the top and bottom of the cylinder. There is a round screen at the top and cylindrical one inside the big cylinder.

Carefully inspect the O-rings and make sure to get them seated in their grooves before tightening the nut on reassembly. The panel around the gascolator on mine also covers the electric fuel pump. Check fittings for blue stains.