How much oil oil should be coming out of the breather tube? engine holds about 35 psi oil pressure after it has been running. Frame and components on the passenger side are getting a really good coating of oil. I noticed this today after going for a 85 mile jaunt.....
Oil pressure doesn't tell you much about the condition of the piston rings, which control compression, blow-by, crankcase pressure, and oil consumption. Do you notice any blue smoke from the tailpipe, especially after coasting for a while and getting back on the gas? It sounds like you're due for a ring job or maybe more serious internal engine surgery. Try doing a cylinder leakdown test to evaluate how well the rings are sealing. It's a lot more accurate than a compression test. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Do you have the Baffle in the engine where the draft tube mounts? My buddy had the same problem and he forgot to put it in when he built his engine. ( said he didn't know it needed to be in) Todd
There are short and long versions of the oil separator part of the road-draft tube. The truck engines seem to have the long version. I believe the purpose of the "baffle" part of the tube is to condense oil vapor back into liquid then drain it back into the pan through a couple of internal holes. You can pry the cap off the fat part of the tube and see the baffle. I had OP's problem some years ago. I had not cleaned the breather when I rebuilt the engine. I took the breather apart. It was clogged with coke-like black stuff. The oil fumes were not condensing and just going out the road-draft tube condensing there and then onto the road, and the frame, and the transmission and everything else. I burned it out with a torch and cleaned out the drain holes, stuck the cap back on with some RTV silicone (not orange) repainted it and put it back on the engine. Problem solved.
1951 3800 1-ton "Earning its keep from the get-go" In the DITY Gallery 1962 261 (w/cam, Fenton headers, 2 carbs, MSD ign.), SM420 & Brown-Lipe 6231A 3spd aux. trans, stock axles & brakes. Owned since 1971.
Ok, No blue smoke when truck accelerates. I took off the tube, baffle tube section is in place and filled with years of accumulated oily goop. I was able to carefully remove the top cap from the tube. Here is what the baffle looks like after I removed some of the goop. There was a lot of goop inside the baffle when I took it off. The inside of the block looked really clean where the tube inserts.
Soak the breather with kerosene or Diesel fuel, place it in a safe area, and light it off. The sludge will burn away to ash, which can be tapped out with light blows from a hammer. It won't hurt the metal of the breather at all and it's a lot quicker than trying to scrub or pressure wash it. Jerry.
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I'll give the kerosene rinse and ignition a try tomorrow afternoon. Someone gifted me a selection of aluminum roasting pans that seem ideal for parts cleaning!
How do your steaks taste after that? "Inquiring minds want to know!" Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
The 1958 Chevrolet Truck Shop Manual (section 8, page 14, CRANKCASE VENTILATION, Standard) mentions that the breather intake filter should be cleaned with a solvent every 2000 miles. Is this filter in the valve cover oil fill cap? If this is what the manual is calling out, will this take the same cleaning as the breather tube? That may be a really dumb question.....
Nope- - - -the "intake filter" is a piece of fiber packing or a piece of aluminum or brass wool in the oil filler cap, and burning that part will destroy the packing. The earlier valve covers had a sealed oil fill cap and slots in the top of the cover with no means of filtering out road dirt. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I got a good look at the filter in the valve cover filler cap tonight. I must have done a great job of cleaning it 7 years ago. The fibrous material in the cap is a nice silver-gray color with a light coating of oil. I don't remember cleaning it out, funny that I do remember masking it off, sand blasting it and giving it a self etching primer and black final coat. I found a friend who has a great parts washer, I cleaned a lot of greasy goop off the breather tube and washed it out for about 20 minutes. It looked like it should soak overnight. Now I am cleaning off the oil from the entire underneath of the truck and installing the tube, changing the oil on Saturday morning. I have been using Pennzoil SAE 30 weight, detergent. Manual suggests this grade when temps are above 32 F. Is this a sound choice for this engine?
That was the recommended "summer weight" oil here in Tennessee for a lot of older engines, with 20W-20 for use down to zero degrees or so in the winter. For the past several years, I've been using 15W-40 Diesel rated oil in everything we own, cars, trucks, lawn mowers, a gas welder, a couple of generators, a pressure washer, and my 97 Harley EVO engine soft tail. No oil related issues whatsoever with any of them! The price of a 5 gallon pail of the stuff from Tractor supply beats buying it by the quart, too! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
