I'll repost a set of dissassembly instructions I posted earlier. You need to do this as a first step withou causing any further damage.
What is causing your pump to "weep' is the main shaft seal is either dirty or damaged. Unless you fix it, it will only get worse over time. You have a couple of alternatives (1) you can replace it with a newer style, small pump--either used or brand new--new they run about $400.00, rebuilt on ebay you can find them for about $300.00--or you can get one off a donor 250/280/SE/SL. In any case you will need an adaptor plate to mount it back on the car. These are available through all the usual sources. You can also buy a rebuilt version of yours on an exchange basis through STAR MOTORS in Endicott, NY--about $250.00 last time I checked--they have a website. As pointed out in my posts, these pumps can be rebuilt. I've done quite a few, but have not taken the step of selling these because I'm not prepared to offer any warrantee or accept any liability on them at this point. The first step in the rebuild, obviously, is to take the pump off the car and disassemble it. Disassembly can be a problem if the pump is pretty rusted up. Here's what I do. Make sure the pump is purged of all gasoline. Undo the two nuts on the top cover--you can discard all the fasteners and washers since you will be replacing them with new M4s on reassembly. The top two should come out fairly easily but in the process you may unscrew the two long threaded rods that hold the top "can" to the pump portion--don't worry about this. They will need to come out anyway. Once the two nuts are removed, take a set of vice grips and using something soft like rubber between the jaws, clamp onto the two stubs revealed by removing the nuts and unscrew them by turning counterclockwise. Pull them out from the "can"--they are about 4- 1/2" long. At this point you should be able to take a flat blade screw driver and remove the top cover by wedging in the slot between the cover and "can". There are two small coil springs that you'll need to collect up. These fit over the two long threaded rods and hold down the brush holder. Once the cover is off you'll need to pry the "can" off the pump body. Use a large flat blade screw driver and pry up against the two slots either side of the can. This will reveal the motor internals including the armature, top ball bearing and brushes. You'll now be able to assess how worn the commutator is. If it is too badly worn, you'd best replace the pump. There are places where you can have the armature rewound with a new comm--this costs about $75.00 and I'm still assessing how well these rewinds work out. With the internals exposed, you'll see immediately what works to destroy these pumps--years of carbon dust build up gets to the bearings and gums them up, especially if there was a leak and the pump was allowed to sit for long periods. Next, go to the bottom of the pump and start to unscrew the slotted screws that hold on the bottom cover plate. If they all come out w/o breaking, great--if they don't, don't despair. What you will need to do is to very carefully pry off the cover. What I do, and you need to be super careful when you do this e.g. wear eye protection--is to take a disposable blade from a utility knife and very carefully with a small hammer wedge the blade in the seam between the cover and the pump body. You may have to use several blades at the same time in order to get enough pressure under the cover to get it off. Again be very careful--you don't want to damage the bottom cover but more importantly you don't want to hurt yourself--you've got a sharp blade and they break/chip very easily. Work your way around the cover using this technique and eventually you should be able to separate the cover from the pump body. You'll probably be left with several "stubs" where the screws broke off. Here's how I get these out. I have a small propane/oxy torch that I set to a fine flame and direct it on the "stub" until it is cherry red. At this point I "quench" the "stub" with WD-40. This usually loosens the "stub" sufficiently where I can get a set of vice grips on the "stub" to unscrew it. Be careful here and do not try to wrestle the "stub' out. I try to wiggle it back and forth a few times so I'm sure not to torque it off. If it is still stiff after this, go back to the heat and try again. If it torques off, you'll need to retap the hole and this is a tough little job to do because the bit has a tendency to slip off the "stub' and dig into the aluminum--not pretty so try to avoid torquing off a "stub". Once the bottom cover plate is off , you can remove the impeller. Note carefully which end of the impeller faces up i.e. towards the pump housing. There is a small woodruff key that lines the impeller to the shaft--it's very small so don't overlook it. You'll need this on reassembly, so collect it up. You can use the "blade" technique if required to remove the eight screws that hold the inlet and outlet cover plates on. When you get the pump disassembled to this point let me know and I'll walk you through the rest of the procedure. Sorry this is so long and detailed, but the job is much simpler than it sounds-- successful disassembly w/o causing further pump/motor damage is key to rebuilding them so be careful.
George Des.
