1925 Buick Oil Pump Issues

[dibarlaw]

3 weeks ago my 1925 Standard oil pressure gage started swinging from 10-15-5-0-15 etc. at speed. Settling to less than 10# at idle. After Reeve enterprise rebuilt my engine and oil pump over 3 years ago pressure had been steady at 22#. We have put over 1,000 miles on the car since then.

 I tried the SW 0-50# gage that was in the car when we bought it. At idle it was barely at 10# warm.

Well I pulled the oil pan yesterday....

 I investigated the oil lines to see if any of the solder joints at brass lines had developed a crack. I had already prepared a replacement oil line assembly from my spare engine to swap out in case. I put some pressure from my airbrush compressor into the system and do not detect any breaks in the lines. But this was probably only arround 10#. I will try a bit more pressure today closer 20# to see if there is any leakage. BUT...

When I checked the oil (rebushed/rebuilt) pump the relief spring was

1 5/16" as opposed to the spec. compressed length of 1 5/8". Free length of 2 1/8". The oil pump from my spare engine had a spring 1 3/4" long. Same # of turns and  same wire dia. The valve is a 1/2" dia. ball bearing. With the shorter spring that was in my car there was evidence of fresh rubbing on the bore by the spring coils.

Now my problem... to source an appropriate spring. I am reluctant to use the longer possibly 97-year-old spring from the spare engine.

I consulted EGGE who rebuilt Hugh's 1925 pump. They have no specs. on the spring they used when setting the pump at 25#. Their only suggestion was for me to send them my pump and match the spring under test. Hugh and I agree that the Buick factory specs may be in error. Shop manual calls for a spring 2 1/8" free length compressed to

1 5/8" at 10 oz.. The spare engine spring is already at 1 3/4" and to compress it to the 1 5/8" took nearly a pound. A similar sized spring (same # of coils and same wire diameter) from a hardware store took 6 lbs. to compress from 2 1/8" to 1 5/8".

 Any other suggestions?

Edited September 21, 2022 by dibarlaw
spelling (see edit history)

[ILIKECARS53]

Are you sure the gauge is working properly?

[dibarlaw]

I tried out the gage that came originaly with my car a newer 0-50 SW and had the same result. Less than 10#.

 I spoke to Edinmass today and took his sugestion of trying a washer first on the old spring before trying other new springs to verify the problem was here at the pump spring. Since I did not have gasket stripped off of the oil pan he sad to just put it back up with 4-5 bolts add the oil and run the engine.

Ed:

 Thank you for the time spent with me on the phone today. We are moving in the right direction. I machined (2) 1/16" thick washers to try with the shorter spring. New gasket on the pump outlet face. Buttoned the oil pan back up with 6 bolts. Put the filtered old oil back in since I will be changing it out when things finaly stabilize. Start up at fast idle ..... steady 30 lbs!

Then I wondered. How much over 30 is the pressure? Disconected the dash gage and ran the auxiliary Stewart Warner 0-50 gage. Just a hair over 30#.

After about 5 minutes of warm up I slowed idle down to where the engine wanted to stall.

 Just to about 22# to where it had been before the problem. I will do a drive around the block tomorrow to see if it varies under turns and stops.

 Thanks again:

 Larry

Hershey spaces   C4M-44-45

 

Edited September 22, 2022 by dibarlaw
Added content (see edit history)

[EmTee]

11 hours ago, dibarlaw said:

I machined (2) 1/16" thick washers to try with the shorter spring. New gasket on the pump outlet face. Buttoned the oil pan back up with 6 bolts. Put the filtered old oil back in since I will be changing it out when things finaly stabilize. Start up at fast idle ..... steady 30 lbs!

So, does this provide enough information to specify a new spring?  It sounds like you have an installed length and spring rate that seems to work.  My concern with the old spring is it appears to be failing from fatigue.  Shimming it will likely be a temporary fix at best.

 

Does McMaster-Carr have anything close to what you'd need?  https://www.mcmaster.com/compression-springs/

[dibarlaw]

EmTee:

 This was just a temporary diagnostic. I will try another NEW spring today. This was just to eliminate the possibility of cracked oil tubes or joints.

[Leif Holmberg]

Take a real lock at the oil lines,I had that oil pressure problem in the 1970 s ,i took me a year to figure out what happend.After I had removed the oil line from the engine I could see a very small crack in the brass tube.

[27donb]

The spring is definitely the "brain" of the oil pressure, by regulating and releasing pressure to maintain a desired pressure.  It seems to me that a trial to find the right spring is the way to do this.  If the original Buick spring specifications can no longer be trusted then shimming a spring might be the only way to dial in the pressure.  If it fluctuates I agree, the spring may be done.

 

The difference between the two spring free lengths might be because someone just stretched one of them to try and get more pressure.

 

According to the shop manual I have, oil pressure for Standard for 1927 is 35-40,  Master is 28-30

 

My 27-25 runs about 32 at speed, drops down to about 10 at idle.

 

I added a shim (washer) under the spring of my 27-54CC (can't remember the thickness, but it wasn't drastic, just a typical washer) and it only raised the oil pressure about 2 psi at about 40mph, hot.  Before that, it was consistently 15psi at speed, dropping to about 8-10 at idle. 

 

I never checked either original gauge with a modern gauge for accuracy.  My Standard has more mileage and has a noisier engine, even though the oil pressure is more than my Master.  I feel the pressure on both is ok and I don't worry about it.

 

My Dad bought the 27-54CC in 1955 and drove it on at least two tours in New England, one up to Canada.  When I got the car from him I asked him what the oil pressure typically was and without hesitation he said "15", so it always ran that way.

 

Both cars were set up by old school mechanics before I was alive with way more smarts than I have.  The key to Buick longevity (IMHO) is not to push them to today's driving limits.  For me that means Standard 35mph, Master 40mph max.  It's where both cars and the driver are comfortable. 

 

Fluctuating oil pressure is probably spring related, however it seems odd to me to have a 30psi reading on a gauge that only goes up to 30.  Gauges typically don't run pinned.  My generator on the 54CC goes to 20 amps, runs at 18 cold and 9 hot, for example.  I would experiment more with maybe a new spring from McMaster Carr, and shims.

Edited September 22, 2022 by 27donb (see edit history)

[dibarlaw]

Leif:

 When I first got the car I had to resolder one on the oil line joints that had cracked open. The previous owner had someone put RTV sealer on it.

 Open joint was at the Cross fitting.

    When I repaired it in 2012.

Later there was a crack in the outer line going up to the rear of the engine to the Y fitting. I repaired that by making a copper sleeve and soldering it.

 

 I soldered up 3 loose fittings on the oil line from my spare engine just in case I needed to replace it on this engine.

 I used the same location fixture I used in 2012. I blanked off the feet that bolt to the mains and pressure tested it up to 30#. This was the 3rd time I redid the joints untill they would hold. Note the soap bubbles at the gaskets at the board.

   

27donb

 I tried the car out on the road today as suggested by Edinmass. Solid 30# on the 3 mile drive but almost to 0 on a right turn but imediately back up to 30. Oil level was probably a bit low after the 3rd drain and refill.

My 1925 BUICK Motor Car Operation and Care states on pg 162.... At a car speed, on high gear, of 15-20 miles per hour the oil pressure is approxomatly 15 pounds per square inch. but will increase or decrease above or below this figure with any increase or decrease in engine speed. Maximum oil pressure is 30 lbs. whilst the minimum figure, as when the engine is running very slowly, is slightly above 0 on the gage."

Well today after the 3-mile trial drive I tried a new spring and it was up to 40lbs. After warm up at fast Idle it was at 30 lbs. Slowing down to just about stalling it was around 10 lbs. At my normal idle range it was holding at 25-28. Reving the engine higher up to say running at 30 mph got back to up 40 lbs. 

 I believe I will try a bit shorter spring to get back to 30 lbs. max so I will not be pegging my 0-30 lb. National gage in the dash.

 I am getting faster at draining, dropping and reinstalling the oil pan!

 

Edited September 23, 2022 by dibarlaw
spelling (see edit history)

[IFDPete]

Larry - about all the oil pan drops.  Do you keep putting on new pan gaskets?  Or did you use sealant on one side of gasket to hold it in place on the pan or block side and keep using the same one.  Premade gasket or make it your self.  Just wondering because I will need to do a pan gasket soon and will probably need to drop and reinstall pan a few times on my 21.

[dibarlaw]

Pete:

 Edinmass said to put the pan back up with 4-6 bolts try and repeat. I had not stripped off the old gasket yet. (my 3rd new one since I have owned the car) And yes, after the drive it leaked a bit but nothing substantial. Hopefully today I will try one more spring and be done.

 My gasket was still available from BOB'S with shipping it was over $65.00 which includes the pan end cork seals. Yours will probably need to be sourced from Olsen's. I would probably make up a temporary gasket if you are going to have to do a drop and check like me. And save the good one for a more permanent fix. I ordered a set of 5 oil line gaskets.(4 on the flanges and one on the pump) from Olsen's. When I called them about just getting those for me he indicated that they would be of the modern gray composite material. The originals were of the copper asbestos variety. The set of 5 small gaskets was $25.00. They could have been sent in a first class envelope sandwhiched between 3X5 cards. Instead using a thin piece of wood shrink wraped in a bubble mailer. Another $9.00 for shipping.

 We all apreciate having things sent well protected. But it was still some overkill.

Shipping costs have been getting painful.

 Sugestions by others to send for springs from various manufacturers (minimum 10 order) and not knowing if they will work. EGGE said to send the pump to them in California to match up a spring. They could not quote me a price or time line to get the work done plus up to $20.00 shipping each way.

My frugal nature kicks in and I have been trying to source as much as I can locally and doing things that I can myself.

Back to the garage for more under car adventure on my back.

 Just saw on the news this morning FEDEX rates are going up 7%!

 

Edited September 23, 2022 by dibarlaw (see edit history)

[Hubert_25-25]

Larry, 

     You are working with 2 factors using the spring that you picked up at the hardware store.  Length and spring rate. 

LENGTH - You may be able to adjust the overall pressure to keep it below 30 psi overall at 2,000 rpm, by continuing to cut the length to lower the overall pressure from 40 psig, but then where are you at during idle? 

 

SPRING RATE - If at idle, the pressure is too low, then I would think the spring is too stiff, rather than too soft.  If the spring were a solid tube, you would see very low pressure at idle because the spring does not respond. 

 

So if you get below 30 psig and you can't get enough pressure at idle, you need to find a slightly softer spring. 

 

Hopefully the spring you are using will get you there.  

Hugh

[EmTee]

On 9/22/2022 at 11:40 PM, IFDPete said:

Larry - about all the oil pan drops.  Do you keep putting on new pan gaskets?

I was thinking about this and concluded that having one of those reusable silicone gaskets like modern cars would be ideal.  Since those aren't available for any of the cars that we're interested in here, I was wondering whether applying a thin 'skim coat' of silicone gasket sealer (or gasket maker) and allowing it to dry completely before installation would offer similar reuse capability.  The key would be to have the mounting flanges clean and keep the silicone coating even; maybe brush it on?

[dibarlaw]

2 more shorter springs have been tried. Pressure 36# and another shorter yet by 1/16"= 32#. I made 2 washers from old, well squished copper crush gaskets, well faced and cleaned up, for a thickness of .095 and placed it under the spring cap nut to bring out the cap out that distance. I wanted to keep as many coils on the spring as possible. It is right at 30# now and does not move further at higher rpms. I will disconnect the test 0-50 gage and reconnect my 0-30 gage in the dash to see how it is effected.

Pan up and down 4 times today.

 As far as Hugh's concern about the spring rates all of this is trial and error. Yes I would like to have a longer spring with more coils to be more reactive, a softer spring.

Going by what the Shop Manual information states, the spring was to be 2 1/8" Free length. Compress to 1 5/8" under a pressure of 10oz. Very, very light. Using all the springs I had under test a movement of 1/2" took about 5.5 lbs.. The other original 1925 pump spring I have with a free length of 1 9/16" took 5.5 lbs to compress the 1/2". So I thought I was in the ballpark.

The original spring in my car had 13 coils but had compressed to 1 5/16" free length. Helped up to 30# output with the addition of 3/16" washer.  When checking that spring just to move it 1/8" took nearly a pound. So I am very skeptical about Buicks spec of only 10oz.

Edited September 26, 2022 by dibarlaw
spelling (see edit history)

[Hubert_25-25]

Larry, 

     As in life, we have to make a lot of compromises.  I hope this helps.  McMaster Carr has a decent collection.  Most spring websites have a minimum order of $60, and even McMaster Carr will custom make any spring for $200 on up.  You better really have done your homework for that one.  So I listed what I could find based on the following criteria.

- min ID is .382

- max OD is .525 (maybe could go to .535)  I am not able to measure that part of the oil pump as it is too deep for my callipers - so using the spring OD plus a small amount.

- original is 13 wraps.  Compressed lg divided by wire size is number of wraps.  I added this to the list.

- my compressed spring needing a washer was 1 5/16", so using 1.5" as minimum length.  Longer lengths chosen as they can be shortened.

- 1/2" at 5.5 lbs is 11 lbs/inch, so maybe looking for something like 8 to 9 lbs? 

So a couple of candidates that may be worth a try.  Put an order in for new wheels for your mechanics creeper too as those may be getting close to worn off.  

Hugh

 

[Fred Rawling]

I make my gasket from a sheet of cork from Michaelks or Hobby Lobby.  I put the pan on the cork and trace the outline of the pan and the bolt holes.

 

For the inside of the gasket,  I use a wood ruler and measure 1 inch in from the outside line to draw the inside of the gasket.  Draw everything before you start cutting.

 

The old fashion way works for me.  I glue the gasket to the pan with yellow weather strip adheasive.  Do not glue it to the engine with weather strip adheasive.  You will be sorry you did that.     To install the pan I use a thin line of Permatex #2 on the gasket. 

 

When I remove the gaslet from the pan, I use a motorized wire brush.

[dibarlaw]

 

I am calling it good.....

Last night I finally dressed the pan to install the new gasket...

 6 times at removing, trying another spring length, bolting up with 5 or 6 bolts and testing again, repeat. The previous spring was what I felt was the same spring rate as the previous sample 5.5 lbs. per 1/2" except it was bright zinc plated just about the same # of coils but at 1 1/2" free length. It pressured up to 34 lbs. I did not want to lose any more coils so I cleaned up some well used copper/asbestos spark plug gaskets bored them to fit, lapped them flat for a total of .095 under the cap to get that spring out farther. 

Pressured up at 32 lbs. 

 The springs for comparison in the photo above left to right. The new 1 7/16" I had tried, the original 1 9/16" free length spring from the parts Kentucky engine pump and the 1 5/16" original from my subject 1925, Beulah.  Again, trying to keep below 30lbs. so as not to continually peg the meter. After this I tried the 1 7/16" spring and it was still too high. I tried one more spring at 1 3/8" and remover the copper washers. The last cold start was 26lbs. So, I called it good, cleaned the pan, installed new gasket. Cleaned bottom face of the crankcase and installed front and rear new corks. Fresh 10W-30. Final pressure as of last night at 11 o'clock was 25 lbs. If I left one washer in it may have been between 26 and 30lbs. But I had had enough!

[dibarlaw]

Hopefully all is well within the engine now. A 9 mile warm up drive had pressure between 25 and 30 # higter reving, pulling a slight hill at about 40 mph. 25-30MPH easy flat drive 20-25 # with a warmed engine.

[EmTee]

How is the hot idle pressure?

[dibarlaw]

EmTee:

 A 10 mile or so drive is what I had done so I considered it a hot engine. Around 20# is where it was at then. For the 4 years after the engine was rebuilt the gage was pretty much at 22# always. Yesterday another 6 mile drive the results were repeated.

 I went to fill up at my favorite NON ETHANOL station. Except that they are no longer were stocking 87 and 89 octane Non Eth. Only 93 oct. at $4.49/gal. Their 87 10% eth. was at $3.86. So I went to our local BJs to fill up at $3.45. Prior to the current administrations energy policy, this station would have non ethanol grades at about 5 cents more than other 10% ethanol fuel stations. Over the last year and a half it has fluctuated as have all fuel prices and availability.

[EmTee]

Sounds like you have the oil pressure regulator issue licked!