Need secret to Jabsco Head repair

[donradcliffe]

I have just finished trying to repair my *&^%$# Jabsco head, and have been stumped again. The lever which switches from wet to dry would not stay on the dry position, making it impossible to pump.

I got out my Jabsco repair kit, which cost half the price of the entire toilet for a few bits of plastic and rubber. Removed the six self-tapping screws which hold the top of the pump on, and put in a new rubber diaphragm. Screwed everything back together, and the pump now leaks badly around the edges of the top. Several iterations of checking for fit with no better results--the new rubber diaphragm just doesn't seal.

This is not the first or second time this has happened to me, so I was prepared and had an extra pump assembly, purchased at 70% of the cost of a new toilet. This solved the problem, but leaves me very pissed off at Jabsco. Why is it that they can pay someone factory wages to assemble a pump which doesn't leak, but my masters degree in mechanical engineering doesn't allow me to duplicate that feat.

What is the secret to reassembling the top of the pump?? I have tried adding silicon to the seal area (still leaked), tightening the screws till the plastic top cracked (really leaked then). Or should I just pay the extra $30 and keep buying replacement pump assemblies?

[Vasco]

You might have the top gasket on backwards. (upsidedown, reversed). I have taken them apart quite a few times but have never had them leak. Make sure the gasket is in properly, tighten screws a little at a time in a diagonal pattern. Do not overtighten screws. On Breathless I have two of them, 5 years (living aboard six months a year) and only have had to change the joker valves. I buy Raritan joker valves which seem to work better than the Jabsco ones.

[captjcook]

Don I have a BSME and can relate to simple mechanical problems that we..well just shouldn't experience! I have a jabsco head which I have rebuilt. It has been some time but as I recall you must install the cap with the wet/dry lever in one position ( or in the middle?) or it leaks because the weights pull on the flapper. Please don't hold me to the fire on this as it has been a long while...but it is my best memory!
Good Luck!

[GordMay]

Open the Flush Control before refitting the valve cover.

For servicing instructions, see the Jabsco Manual Toilet Technical Data Sheets (pages 6 & 7) at:
http://www.ittjabsco.com/files/29090...data_sheet.pdf

2. Servicing - Seal replacement
If water begins to leak around the piston rod (key 29) at the top of the pump, the seal assembly (key 18) is worn and must be replaced.
YOU WILL need:
■ A Seal housing Assembly 29044-2000.
▼ Unscrew the seal housing assembly (key 18) using a 24mm (15/16") spanner and remove the entire piston rod assembly from the toilet.
▼ Wrap some tape around the piston rod within 16mm (5/8") of the handle. Grip the piston rod through the tape, unscrew the handle and remove the bumper washer (key 25). Remove the tape.
▼ Slide the old seal assembly off the piston rod. Wrap one turn of tape around the thread at the top of the piston rod to protect the new seal and slide the new seal assembly onto the piston rod. Remove the tape from the thread.
▼ Wrap some tape around the piston rod within 16mm (5/8") of the handle. Grip the piston rod through the tape and replace the bumper washer and handle. Remove the tape from the piston rod.
▼ Slide the whole assembly back into the pump cylinder and tighten in place.

CAUTION: Gripping the piston rod with a tool anywhere except on the 16mm (5/8") below the handle damages the surface in a way that causes rapid seal failure.

4. Servicing - Overhaul
YOU WILL need:
■ A Service Kit, part number 29045-2000, which contains all wearing parts - refer to the PARTS LIST for details. Remove the pump assembly as follows:
▼ Loosen hose clips; disconnect the inlet hose and the flushing water hose (key 4) from the top of the pump.
▼ Remove the 2 screws (key 31) that secure the discharge flange (key 32) that holds the discharge elbow (key 34) and hose to the pump cylinder (key 28).
▼ Do NOT remove the hose from the discharge elbow.
▼ Remove the 4 screws (key 31) that secure the pump cylinder to the base.
▼ Lift off the pump assembly and pick up the base valve gasket (key 16) and the joker valve (key 33).
Dismantle the pump assembly as follows:
▼ Remove the 6 screws (key 26) that secure the valve cover (key 27).
▼ Open ( ) the Flush Control (key 23) before lifting off the valve cover assembly and picking up the top valve gasket (key 21) and the valve seat (key 19).
▼ Remove the handle and the seal assembly by following the SERVICING INSTRUCTIONS for SEAL REPLACEMENT.
▼ Withdraw the piston assembly (key 29) and prise off the piston O-ring (key 30).
▼ Do NOT remove the bowl from the base
▼ Clean and disinfect all parts - refer to OPERATING INSTRUCTIONS for CLEANING. Remove scale from the cylinder bore.
▼ Inspect the top and bottom valve gaskets (key 21) and the joker valve, and renew them if they are damaged, stiff or covered with scale. Automatically renew the seal assembly and the piston O-ring. Use the other parts in the kit as necessary.
Reassemble the pump as follows:
▼ Push on the new O-ring and lubricate with petroleum jelly (vaseline).
▼ Following the SERVICING INSTRUCTIONS for SEAL REPLACEMENT fit the new seal assembly, the piston assembly and the handle.
▼ Lubricate pump cylinder bore with petroleum jelly (Vaseline).
▼ Locate the valve seat on top of the cylinder, locate the top valve gasket on its pegs on top of the cylinder and Open ( ) the Flush Control before refitting the valve cover.
▼ Locate the joker valve in the discharge elbow.
▼ Secure the discharge elbow and hose to the cylinder, using the discharge flange, BEFORE you refit the pump assembly to the base, so that the joint is not under leverage from the discharge hose. If you do not, the joint may not seal.
▼ Locate the bottom valve gasket on its pegs on the base
▼ Secure the pump assembly to the base whilst relieving any leverage from the discharge hose. If you do not, the joint may not seal.
▼ Examine all hoses throughout their length for chafe, kinks and splits under hose clips. Check all hose clips for corrosion and replace worn or damaged parts.
▼ Reconnect all loose hose ends and secure them with their hose clips.
▼ Ensure that the base drain plug (key 8) is securely in place.

CAUTION: Do NOT lubricate top or bottom valve gaskets. Do NOT apply sealing compounds to any gaskets or hose connections.

[Vasco]

Think you're right captjcook, it has to be tested with the cap off and then screwed down in the dry position, if I remember right. Takes a bit of jiggling.

[stevensc]

There was a change made about 1998? the heads look similar but the kits have different numbers and some differences, I don't know what they are.
be sure you have the correct kit.
Steve

[captjcook]

Thanks Vasco! Gord did the one thing that a mechanical engineer would almost never do...read the corrections (instructions)...I had to figure the problem out on my own...The engineers curse lol! We are driven to understand how things work.
Jim

[Ex-Calif]

I looked at the build kits for our Jabsco. At 70% of new I opted to buy a new head which came with a new seat, all new plastics that were not brittle etc.

There is satisfaction from fixing things that are broken but to my knowledge there is absolutely no satisfaction to be gained from working on sanitation systems...

[RBEmerson]

Honest - lose the darn thing. A friend who's been a plumber most of his adult life finds his Jabsco head almost unmanageable. I went with a Raritan Engineering Compact II and, aside from a problem with the piston (RE replaced the part out of warranty), have had no problems.

[Lancerbye]

I have to agree with RBEmerson, have had a few of those over the years in different boats. I find the answer to be a Sealand Vacuuflush. Will never go back to a Jabsco, a Par or any of the pump and switch types again. I have been spoiled.

[sneuman]

The dirty little secret to Jabsco head repair? Toss the thing overboard and buy a Lavac, Groco or Raritan. Jabsco's are worthless.

Seriously, by way of empathy, I have done exactly the same "repair" you are talking about and had exactly the same results.

[donradcliffe]

Thanks for all the feedback. I had to replace my Raritans when both of them cracked their bases within a month, so I wasn't really ready to pay twice for Raritan replacements as much as for the Jabsco cheapo's...

There are now three separate service kits for the Jabsco, and even big chandleries don't seem to consistently stock all three. Jabsco must have imported some engineering talent from Detroit....

The positioning and alignment of the top gasket was the first thing I checked. I even read the instructions, and the only thing I was doing differently was using silicone grease instead of the recommended vaseline on the piston seals.

Other than adding unnecessary plastic to the environment, I'm convincing myself the best solution may be to plan on buying an entire head every 4-5 years, and carrying a couple of replacement pump assemblies ($99)rather than repair kits ($67).

[RBEmerson]

Done is done and all that, but did you try calling Raritan about the cracked bases? Vic Williams (head customer support person) is very good with coming up with solutions that answer problems well.

[gonesail]

get a raritan PHII. easy to maintain and rebuild if need be. works like a charm.

[Rhosyn Mor]

The secret to repairing a Jabasco head is to install a Lavac. If you are anywhere near the chesapeake, there are two being given away at one of the repair yards here