PDA

View Full Version : Oil Pump Vacuum question


430MEL
03-18-2007, 06:53 PM
Just sent my wiper motor off to Ficken. I am now replacing all my Vacuum lines and did a test of the vacuum line coming off the oil pump (I have 1960 430). Does this pump provide vacuum all the time while the motor is running. Mine is not showing any vacuum at any RPM. Motor was rebuilt by previous owner and he "cant" remember if the oil pump vacuum was replaced. I'm getting great oil pressure so the pump was replace. Either the vacuum pump is broken or missing or the check valve is install the wrong way-as was the case on my power brakes!! Going to crawl underneath it next weekend and check ,if the weather warms up!. The vehicle also has a fan shroud which the PO says was from a 1961 Lincoln 430 and it looks like it was made for it, all metal and fits perfect. Anyone use one of these shrouds. Ill post some pics as soon as my daughter get home from school for summer break, as she took "my" new digital camera with her!!

KULTULZ
03-18-2007, 07:18 PM
The vacuum pump should work while the engine is running. The check valve for this application screws into the left block skirt so reverse assembly is not possible.

There was a lengthly discussion a while back on vacuum wipers and should be found with a search.

JohnG
03-18-2007, 09:13 PM
I believe you are at the correct sources for the problem: check valve(s). Since they are 1-way valves, you can have a problem due to either one failing or one being in backwards.

If you can get the pump out on the bench and remove the valve(s), you can bench test them by putting a hose of some kind onto each and seeing if they only pass air one way.

Cleaning one out might help matters. If that fails, you can probably get a rebuild kit.

There is possibly also a diaphram which could be leaking air.

I have not worked on the pump for the 430 so all this is speculation on my part from working on a cam driven fuel pump from my 352 FE motor. However, a vaccum pump is a vaccum pump...

John

430MEL
03-20-2007, 09:10 PM
Hey thanks for replies. I think the PO replaced the original vacuum pump/oil pump with just a oil pump. Iam getting no vacuum at the hole on the exit hole on the side of the block. I see those pumps on Ebay now and then. They were a supplement to the regular intake vacuum. I don't plan on driving much in the rain-too much car to clean! So I dont know if I'll replace it. Getting strong enough vacuum from the intake.

JBird
03-23-2007, 01:25 PM
Hey thanks for replies. I think the PO replaced the original vacuum pump/oil pump with just a oil pump. Iam getting no vacuum at the hole on the exit hole on the side of the block. I see those pumps on Ebay now and then. They were a supplement to the regular intake vacuum. I don't plan on driving much in the rain-too much car to clean! So I dont know if I'll replace it. Getting strong enough vacuum from the intake.

The vac pump on the oil pump only works when needed because the intake vacuum is normally greater and keeps the check valve closed.

Passing in the rain or pulling uphill causes you to press on the gas pedel harder and open the carb butterflys more. That lowers the intake vacuum. At that point, there is a vacuum switch mounted on your wiper motor. It's my understanding that it automatically will switch to the greatest source of vacuum.

As the intake vacuum drops, the engine RPM's pick up as the transmission downshifts. That causes the oil pump and piggyback vacuum pump to spin faster and create more vacuum than the intake has. This switches the wiper motor source over to the oil pump and the check valve opens.

Your wipers will continue to work, not stall.

If the check valve is not seated or leaking you will suck oil which lubricates the vacuum pump past the check, through the vac. lines and into the intake which makes you think you have bad rings because of the blue oil smoke. A normal compression check would point to the vacuum check or a transmission modulator with a bad diaphram. The latter causes blue exhaust but also causes tranny fluid to go low and may cause slippage and a poor shift between 1st and 2nd.

If you don't get any vacuum from a running motor there are only 3 causes.

1.) The vacuum tubes are not connected inside the block or they are leaking.

2.) The vacuum pump is damaged or

3.) Your mechanic (like mine did) didn't have a clue what the pump did and left it off. Lucky me. I caught my rebuilder's error before the pan went on and gave him all the info I had on the vacuum pump.

jbird

LuckyJay
03-23-2007, 05:05 PM
Am I missing something here? These old Fords had a duel purpose Fuel pump. To supply fuel to the carb and supply vacuum. All this talk about oil pumps for vacuum makes me wonder how many are pumping oil to the carb.

430MEL
03-23-2007, 09:44 PM
Thanks JBIRD, so I should still have a reading from the oil pump vacuum with the engine at idle. I hooked up to the oil pump vacuum line and raced the motor off idle I did not get any reading so my pum is not working or missing.