Refurbishing Jabsco Par 36800 High Pressure Water Pump

The Jabsco PAR 36800 high pressure water pump has been around for a long time and is found on many boats because it has many features that make it best in class. Not the least of which is the ease of maintaining and repairing it.

The second thing that makes this pump desirable is the fact that it can be run dry without damaging it. Running a pump dry happens all the time on Mai Tai so this feature is high on our desirability list.

I can tell you based on 15 years of use that these pumps are very reliable. But, there are times when something will fail. In our case it was the pressure switch. This post runs you through the breakdown and repair of Mai Tai’s water pressure pump.

Opening the Jabsco PAR 36800 high pressure water pump

Jabsco 36800 series parts

Jabsco 36800 series parts

These pumps are very simple and easy to work on. They have three rubber parts inside that sometimes degrade and need replacement. Then there’s the motor and a belt that drives the pump. I have yet to have a problem with these (after 30 years of service). Finally, this pump has a pressure switch. Which is what failed in our case.

After removing the pump from the system, which was the hardest part of this process, I wanted to check the rubber parts in the pump housing. At the same time I ordered a new pressure switch. Click HERE for a spec sheet PDF.

The rubber parts in our pump were all in serviceable condition. The motor is in good condition. So, the only part I needed to return this pump to service was the pressure switch.

Parts Availability

Parts are available for everything you need. I found several sources by doing a simple search. One company offering all the parts anyone could need is Pump Agents. I like their website because it’s easy to search and has a complete line of parts.

In our case we only needed a new micro switch. Pump Agents had the switch and sent it promptly. Removing and replacing the switch was simple. It’s not necessary to replace the switch housing.

Jabsco Pressure Pump Body

Jabsco Pressure Pump Body

This pump is 30 years old. This is a good time to replace internal rubber parts, like the diaphragm and control valves. They were not expensive and would ensure against future failures.

I opted not to replace the rubber pulsation dampener. It is constructed of heavy rubber and showed no signs of cracking, deformation or stiffness.

Jabsco Pressure Pump Flow Control Valves

Jabsco Pressure Pump Flow Control Valves

The last parts I replaced were the rubber vibration dampeners that insulate the pump from the floor (the feet). I also have a spare belt connecting the motor to the jack shaft. Although I’ve never had one break.


This style diaphragm pump is efficient, relatively quiet and easy to service. It is a very reliable pump that cruisers can, with a few spare parts onboard get back up and running in a few minutes no matter where you are.

If your boat came equipped with these pumps I’d think long and hard before replacing it. New ones are pricey compared to the more modern impeller pumps. But, the cost of repairing them is a better deal than replacing them the newer style pumps.

Another advantage of maintaining them is that many of the parts for the pressure pump are interchangeable with your other pumps. Like drain/sump pumps, or even the pumps that run your vacuflush toilets.

Note: We have no affiliation with or interest in any of the vendors referenced in this article.