oil pressure relief valve

discussions specific to the 906 Paso
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odd duc
Posts: 26
Joined: Wed Mar 09, 2016 12:47 am
model: 906 Paso
year: 1990
Location: USA

oil pressure relief valve

Post by odd duc »

If I'm reading the service manual correctly the oil pressure relief is only accessible after splitting the case halves. somebody please tell me there is an easier way. I'm trying to solve a low oil pressure problem in a freshly rebuilt engine and would prefer not to pull the motor apart again.
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paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: oil pressure relief valve

Post by paso750 »

usually problems with the oil pressure relief valve would lead to high oil pressure.
As the engine was freshly rebuilt I wonder if there`s air in the oil pump and it lost its prime. In that case you could try to remove the upper plug on the front right of the engine (the one above the oil pressure switch, where on other Ducs the exit hose to the oil cooler is attached) and pour in some oil there. Then wait and try again.

Excessive oil would have to be removed again however trying that would be easier than splitting the engine.
odd duc
Posts: 26
Joined: Wed Mar 09, 2016 12:47 am
model: 906 Paso
year: 1990
Location: USA

Re: oil pressure relief valve

Post by odd duc »

does it matter which hole the sender is in? I've noticed that the service manual shows the sending unit in the lower hole yet some other resources and pics show it in the upper. mine has had it in the upper hole since I bought the bike a few years ago.
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paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: oil pressure relief valve

Post by paso750 »

the parts catalogue also shows it in the lower hole.
If it makes a difference I don`t know specially if both holes are above oil level.
Maybe someone else here knows?
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Derek
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Posts: 768
Joined: Thu Nov 03, 2011 10:13 am
model: 907 I.E.
year: 1994
Location: Scotland

Re: oil pressure relief valve

Post by Derek »

Weirdly I experienced this exact problem today.
I fired up the 907 after the winter lay up and service and the oil light stayed on. So I removed the oil pressure switch, it's in the top hole on my bike, and with an oil can squirted oil in until it filled up. I refitted the oil pressure switch and fired the bike up. The light went out instantly :)
In my many years of Ducati owning I have heard of this air lock problem but this is the first time I've experienced it.
1994 907ie
2017 Supersport 939
2015 Scrambler Classic
1982 Pantah 500SL (now sold)


Scotland
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paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: oil pressure relief valve

Post by paso750 »

Derek, out of curiosity. The oil pump is on the right engine side. Did you have the bike parked on its side stand over the winter? Just wondering if that could cause air getting into the oil pump.
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Derek
paso grand pooh-bah
Posts: 768
Joined: Thu Nov 03, 2011 10:13 am
model: 907 I.E.
year: 1994
Location: Scotland

Re: oil pressure relief valve

Post by Derek »

No, I parked it on the centre stand but after draining the oil I left it for a couple of months before refilling. This may have allowed the pump to drain and hence the subsequent air lock. I didn't change the filter because it had only done about 1,500 miles last year.
1994 907ie
2017 Supersport 939
2015 Scrambler Classic
1982 Pantah 500SL (now sold)


Scotland
bigdjag
Posts: 4
Joined: Wed Nov 16, 2016 8:08 am
model: 906 Paso
year: 1992
Location: Scotland

Re: oil pressure relief valve

Post by bigdjag »

You can get the relief valve out without splitting the casings. Remove the alternator cover and beside the gear shift shaft there is a brass looking plug remove it and you can get the valve out
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