On 3/24/05 0:01, "Jonathan Farrugia" <jfarrugi@UMICH.EDU> wrote: > we don't measure the pressure differential because of the cost to > implement the system, ie the plumbing. this is done industrially > primarily where the system doesn't have a relief valve, or one is not > desired. > > jonathan > > On Wed, 23 Mar 2005, Jere Hawn wrote: > >> HI again, >> >> In the Navy we use pressure differential across the filter to determine if >> it needs to be cleaned or serviced. If my memory is correct if the pressure >> from the inlet side of the filter was 10 lbs greater than the outlet side >> then the filter needed attention. Why don't we use this? Has anyone heard >> of it? Is there any way to tell? >> >> >> >> Jere VW makes some heavy diesel and gasoline commercial engines and it would not surprise me to find that system was brought over from the commercial engine side of the house. The high pressure oil pressure switch is on the outlet from the oil filter. If the filter becomes clogged up it will not be pushing out enough oil to close the switch. (lower switch is NO) the switch on the head is NC. Because of the setting of the lower switch, it will trigger very easily if oil is too thin, filter not flowing well enough, or if oil has foamed, or tube sucked air. Any of these and you can still have enough oil getting to the heads but pressure to the bearings may not be enough and you will get oil pressure lights. However anything more than a momentary that also effects the upper pressure switch will trigger as well, then you get the oil light at full light and alarm(if your vehicle had the alarm). experimenting I did with a jetta that had failure of the dynamic system was interesting. I replaced the or/nor gate system with two oil pressure lights. I have done this on two jetta. •••••••••••••••••••••••••••••••••••••••• jimt Planned insanity is best. Remember that sanity is optional. http://www.tactical-bus.info (tech info) http://www.westydriver.com |
Please note - During the past 17 years of operation, several gigabytes of
Vanagon mail messages have been archived. Searching the entire collection
will take up to five minutes to complete. Please be patient!
Return to the archives @ gerry.vanagon.com
The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.
Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.