Crank pulley out - Oil pump still in and Pump Q's

You can remove the oil pump without the special tool. Unscrew the case bolts around the pump, to loosen the fit a bit. Then you can use two screwdrivers as levers to pry the pump off. Place the screw drivers under the two special tabs on the pump's flange, that are provided for this reason. You must try to pull the pump as straight as possible. If it tilts in its bore, it will stick. You have to drain the oil first (if you haven't allready). Heating the case surrounding the pump with a propane torch, will help too.

32mm gears are too much IMO. The much larger oil pressure when the engine is cold, will blow your oil filter or oil cooller and seals. Do not rev the engine until the oil has warmed up. Also the 32mm pump is wider, and you might have interference problems with the tin plate that goes behind the pulley. This will be pushed outwards and rub on the pulley. If it is possible, change the 32mm pump with a 26mm. If you have the stock exhaust, the manifold preheat pipe interferes with the oil filter in most of the filter-pumps, except the one that is provided with the new stock mexican engines, which is angled towards the bottom. The problem with this pump is that the axial end play of the gears is usually excesive, resulting in low oil pressure. You have to careffully file flat the pump's body (with the gears installed) on a wet or dry abrasive paper, layed on a flat surface with some white spirit on it, until the clearance gets to zero. Use a random pattern and rotate the pump as you file it. The paper gasket will provide the necessary clearance. Keep in mind that a filter pump won't last as long as a stock pump, cause the cover is alluminum and wears quicklly.

Bill, '67 Bug.

Thanks a lot Bill, I'll remove the pump tonight. According to the Hayes and Bentley manuals, I don't have to drain the oil. I already removed the cover, and just a few drops of oil came out. I'm afraid to use the torch around there to heat it, gas in the oil and explosions come to mind.

If the oil pressure will be excessive only when cold, I can live with that, the weather here is hot, so engines warm up really fast. What I'm going to do is get an oil temp and an oil pressure gauges, What are the "safe" temp and pressure ranges?

Luckily, It doesn't seem to be any clearance problems with the engine tin or the exhaust. Here mexican parts are a dime a dozen, so very few german cars remain 100% german. even my case is a late mexican. Nevertheless, I haven't checked for axial endplay on the new pump, I'll do that first.

Thanks again for your help. Karls

screwdrivers

You can heat the case before removing the pump cover, or you can run the engine for a few minutes if it still runs. The pump is bellow the oil level, so oil will pour out when you remove the pump, and will make a mess. You can jack the back of the car up, if you don't want to drain the oil.

You may use a high pressure oil filter to prevent it from blowing durring cold startups. If the oil relief valves in the case are in good condition, you won't have any problems with overpressure. Only the oil filter and left side of the pump cover see the high pressure when cold.

Bill, '67 Bug.

Since you have a larger pump, leaving an axial play of about 0.15 mm wouldn't be bad, as this would reduce oil pressure a bit.

Bill, '67 Bug.

How do I check the oil relief valves?

Thanks again, Bill

You either hope they work... or

Remove the plugs at the bottom of the case, get the springs and pistons out. Check that the springs have the correct length unloaded according to the specifications, then you have to check for the correct length when loaded with a certain weight. Normally you would need a speciall tool for that, but you may be able to fabricate an arrangement that would permit you to measure the spring's rate. I don't have the specs available right now, someone else could help. Also check that the pistons are not binding in their bores and that they are smooth.

Bill, '67 Bug.

Another draw back of a large gear/high pressure pump, is the fact that most of the oil will bypass the oil cooler even after fully warmed up! I have experienced this on my own car after/on long full throttle runs.... Runs VERY warm..

J.

That's when you mess with the first oil pressure relief valve, increasing the spring tension so more oil would be forced into the cooler. Resulting in bulging cooler passages (air won't get past them as the passages swell and the air gap between them is eliminated, a problem with the old style cooler at least) and you get blown seals and oil lines too..

But sure, you can force it through the cooler.

Bottom line is: the engine rarely needs anything more than the 26mm pump. Oil pressure problems at idle come from elsewhere, they are not caused by the pump. (well, usually aren't)

The excess pressure (oil)is bled back into the case without ever making it's way to the bearings. OTOH, when pressure is increased dramatically, teh bleed won't flow enough to bleed off all of the extra pressure and then the pressure will climb thoughout the system.

Jan

Another thing to consider is that you will probably need a deep sump, cause the 32mm pump can pump oil from the sump faster than the oil returns there. You might not be able to detect this by the oil light coming on, cause the horizontal oil filter will mix the air with the oil and send oil foam to the oil system.

Bill, '67 Bug.