lobo Posted November 10, 2011 Share Posted November 10, 2011 We always used 20w non detergent in the past. I can find 30w non detergent now but no 20w. Our 87 mack uses 15w40 in steering reservoir. Any ideas? thanks Quote Link to comment Share on other sites More sharing options...
miro Posted November 10, 2011 Share Posted November 10, 2011 Mack recommended 15/40 oil when it came out. ATF before that. Found 15/40 worked better. Quote Link to comment Share on other sites More sharing options...
lobo Posted November 10, 2011 Author Share Posted November 10, 2011 Thanks miro, I was going to use 15w40 before I found this site. I remember some people telling us in the old days that detergent oil would foam up in those old pumps. Thanks Quote Link to comment Share on other sites More sharing options...
Rob Posted November 10, 2011 Share Posted November 10, 2011 I still prefer and use ATF Dexron II fluid. I also like, and use, power steering coolers. I've never had problems and the steering is not "notchy", or requires increased effort during winter months when cold.Those with engine oil in the reservoir have been changed years ago.Not saying this is right, but it does work for me.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
lobo Posted November 10, 2011 Author Share Posted November 10, 2011 Cold weather is what made me check oil level. Steering was getting a little stiff and making a growling noise. Fluid was about 1.5" low. I noticed belt is a bit loose also. If I ever need to change out the hoses and lose oil I may refill with ATF. Thanks Quote Link to comment Share on other sites More sharing options...
ducky698 Posted November 11, 2011 Share Posted November 11, 2011 Hi, i use dextron 3 or 2. Tranny oil is designed not to change its viscosity. And when ur chaseing 2 trailers an a dolly to hook up to the 3rd trailer u need ur steering Grant Quote Link to comment Share on other sites More sharing options...
Rob Posted November 11, 2011 Share Posted November 11, 2011 Cold weather is what made me check oil level. Steering was getting a little stiff and making a growling noise. Fluid was about 1.5" low. I noticed belt is a bit loose also. If I ever need to change out the hoses and lose oil I may refill with ATF. ThanksThere should be a filter in the reservoir also. Might not be a bad idea to drain the system, change the filter, and refill. That would be a great time to change over. I'd run a quart of ATF through the system with the return to reservoir line disconnected while cranking the engine over with the engine kill cable pulled out. This will allow the system to flush.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
lobo Posted November 11, 2011 Author Share Posted November 11, 2011 Good idea Rob, and thanks for helping out a new guy here. Very good site. Quote Link to comment Share on other sites More sharing options...
Rob Posted November 11, 2011 Share Posted November 11, 2011 Good idea Rob, and thanks for helping out a new guy here. Very good site.You are quite welcome. This is without a doubt the best site on the net dealing with Mack Trucks and related products.The people make it what it is.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
MACKS Posted November 11, 2011 Share Posted November 11, 2011 Been using 15/40 motor oil for years and have no problem even in bitter cold weather, why use tyranny fluid when Mack recommends motor oil?If it's a hobby truck ok but if your running every day I think you should use what Mack recommends,can the tyranny fluid lubricate the pump as well as motor oil,just asking because I don't know and I'm thinking that's why they recommend the motor oil. Quote Link to comment Share on other sites More sharing options...
miro Posted November 11, 2011 Share Posted November 11, 2011 The detergent in the oil does not foam up, what it does is hold the dirt in suspension, thats why you use none detergent in none filtered engines, to let the dirt fall out and not get circulated,in a normal engine with a filter the filter traps the dirt. ATF is a high detergent oil with a viscosity rating of about 10 but is not multi viscosity. The Ideal thing really is to put hydraulic oil in the system but you probably would not be able to turn the wheel in winter with summer grade and would burn out the pump with winter grade in the summer because it would be to thin once it got hot. Quote Link to comment Share on other sites More sharing options...
Rob Posted November 11, 2011 Share Posted November 11, 2011 Been using 15/40 motor oil for years and have no problem even in bitter cold weather, why use tyranny fluid when Mack recommends motor oil?If it's a hobby truck ok but if your running every day I think you should use what Mack recommends,can the tyranny fluid lubricate the pump as well as motor oil,just asking because I don't know and I'm thinking that's why they recommend the motor oil.I don't have a good answer as to which is better or why. For years all the OEM companies ran and specified ATF in their power steering units for lubrication. I do know by design criteria ATF does shed latent (absorbed) heat faster that conventional engine oil and that may have had something to do with it but as Grant mentioned; ATF is designed to have more viscous stability throughout it's operating temperature range that engine oil. I'm not a big fan of multi viscosity oil myself although I run 15W40 in my four stroke diesels. I'm a very strong holdout in "old technology" that actually works.The detergents in motor oil do not actually "scrub" the internals of an engine. These additives actually hold contaminates (by products of combustion) in suspension until the oil filter(s) can capture and contain it. These type particulates do not exist in a power steering system. My personal belief is streamlining of products on the assembly line is the reasoning behind the change, although I have no proof of any kind. I change all fluids on my vehicles ever 24 months including power steering fluid and it is replaced with ATF. Never had any problems.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
miro Posted November 11, 2011 Share Posted November 11, 2011 You are right Rob, power steering is is just a closed hydraulic system, and the oil you put in really does not matter to much whether it is detergent or none detergent, I have never heard of power steering failing because you used atf or engine oil. The oils are more critical to engines transmissions and diffs. Quote Link to comment Share on other sites More sharing options...
ducky698 Posted November 12, 2011 Share Posted November 12, 2011 Hi, ATF is also used in a lot of manual gearbox,s to so they change gears when cold.Grant Quote Link to comment Share on other sites More sharing options...
Mack Doctor Jr. Posted November 16, 2011 Share Posted November 16, 2011 I've also been torn what to put in them. My dad says 15/40 for the main reason is if the pump seal goes out all ur doing is putting the same type of oil in the engine that is already there. Quote Link to comment Share on other sites More sharing options...
Rob Posted November 16, 2011 Share Posted November 16, 2011 I've also been torn what to put in them. My dad says 15/40 for the main reason is if the pump seal goes out all ur doing is putting the same type of oil in the engine that is already there.That does sound like a logical reason but ATF, (Dexron) readily mixes with any engine oil. A lot of old timers used to use a quart of Dexron in the crankcase prior to oil change as a flush for gum and varnish.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
rhasler Posted November 16, 2011 Share Posted November 16, 2011 Starting in February 2006 Mack started factory filling the CXN, CHN, and CXP with Dexron III. The '07 emission and later trucks are using Dexron III. They also have a plate type power steering cooler, that's mounted in the right frame rail next to the engine, but I've seen a couple of the newer trucks with a fin and tube heat exchanger mounted in front of the radiator. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment Share on other sites More sharing options...
redington Posted November 16, 2011 Share Posted November 16, 2011 (edited) I have an 81 RS612 with over two million miles on it and I have always used Rotella 15/40 in my power steering pump with no problem. Hope this helps. Edited November 16, 2011 by mack2000 Quote Link to comment Share on other sites More sharing options...
shortstack Posted November 19, 2011 Share Posted November 19, 2011 For what it's worth, my own experience, I always used ATF. When I got my CH, it had some power steering leaks. I replaced a few o-rings and refilled with ATF. Seemed like about once a year the top seal on the gearbox would start leaking as well as the o-rings. Got to reading the owner's manual and it said to use motor oil so I changed the filter and oil to 15W-40 and don't seem to have near the problems as before. Seems with the ATF the seals got hard. Got a '08 Granite that uses ATF though, so don't have a good answer, just what has worked for me. Trey Quote Link to comment Share on other sites More sharing options...
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