peterg123 Posted February 8, 2018 Share Posted February 8, 2018 (edited) Hi Guys 1 have an 87 Defender 110. My original Hoburn Eaton PAS pump leaked at long last. It was also screeching before it reached full lock, as the pulley seized. Had to back the steering lock bolts further and further out. Was not screeching/seizing like this from new,but as it developed over past year or two I still had to un it a few thousand miles of African bushwork in "screech" mode as I had work to do. The further I drove, the worse the screeching would get when on full lock.I have changed the PAS for a new Britpart equivalent . Surprise that it still screeches. Changed PAS pump belt. Screeches. (a) Some owners can get about 15mm between the tyre and the front link on full lock. Mine is screeching at 70mm distance. So I have very poor lock indeed. Any attept to go below 70mm and the screeching gets horrendous. (b) The belt is toothed. What have a toothed belt and a plain pulley? (c) I have tensioned the PAS pump belt all the way as far as it will go, and still have an inch of slack. I reasoned that this belt had to be very tight to drive the pump under extreme lock when the ADWEST PAS steering gear is putting massive pressure on the PAS pump. But I cant tighten further, there is no adjustment left in the slotted PAS pump mounting plate. (d) Therefore could it be the actual PAS pump pulley ET5783 is worn and that is why the belt is slipping and PAS pump locking up then releasing in a cycle? Ideas welcome folks. Thanks Peter Nairobi Edited February 8, 2018 by peterg123 Typos Quote Link to comment Share on other sites More sharing options...
elbekko Posted February 8, 2018 Share Posted February 8, 2018 I'd look at the steering box, the pump doesn't care how far the wheel is turned as long as it's not full lock. Quote Link to comment Share on other sites More sharing options...
western Posted February 8, 2018 Share Posted February 8, 2018 Don't hold full lock on for more than 30 seconds is LR's info in my defender workshop manual, or it'll trash the relief valve, the screech could be caused by a damp or slipping/loose PAS belt. Quote Link to comment Share on other sites More sharing options...
peterg123 Posted February 9, 2018 Author Share Posted February 9, 2018 (edited) I have had success ditching the Europart Chinese PAS pump belt, having found an older one made in Denmark. The Britpart ones are longer and thus cannot get the proper adjustment tight enough to stop the slipping and subsequent squealing. Edited February 9, 2018 by peterg123 Change 1 Quote Link to comment Share on other sites More sharing options...
Troll Hunter Posted February 9, 2018 Share Posted February 9, 2018 The screeching noise is possibly caused by brake fluid being released through the pressure release valve. This could be due to a power steering box problem causing the fluid pressure required to achieve full lock being higher than normal, or it could be due to a deterioration of the pressure release valve passing fluid at a lower pressure than design. I don't know how you could check out these conditions without installing a pressure gauge in the high pressure supply from the pump. Possibly you could swap the steering box for a known good unit, if available. Mike Quote Link to comment Share on other sites More sharing options...
peterg123 Posted February 9, 2018 Author Share Posted February 9, 2018 (edited) Thanks Mike but if you put brake fluid in your PAS pump, you will be in for rouble! That said, yes, that could be the problem- in the PAS box rather than the pump. What I discoevred is, if you go for a proper Land Rover belt, it's fine..even a Britpart one....the Europart ones caused my problem... The steering box might have been labouring at travel of the PA rack rack ast point X...but as I have not a spare I'll go with the solution of the better belt for the moment. The Europart belts are 75.25mm O (sorry 73.5 CMS!)D, the original LR and Britparts ones are 73.5 mm (CVMS!--edit). Herein the prob! You cant get the Europart one tight enough. Edited February 9, 2018 by peterg123 Typos Quote Link to comment Share on other sites More sharing options...
Troll Hunter Posted February 9, 2018 Share Posted February 9, 2018 "The Europart belts are 75.25mm OD, the original LR and Britparts ones are 73.5 mm. Herein the prob! You cant get the Europart one tight enough." peterg123, thanks for pointing out my typo. Yes, power steering fluid obviously. I think in your post you meant width not OD or cm not mm. Touche! We all need a little help from our friends. However, if the Europart belts are smaller diameter, why can't you get them tight enough? I'm totally confused Mike Quote Link to comment Share on other sites More sharing options...
Stambecco Posted February 9, 2018 Share Posted February 9, 2018 European is larger😉 Quote Link to comment Share on other sites More sharing options...
peterg123 Posted February 9, 2018 Author Share Posted February 9, 2018 (edited) Dear Troll Hunter.....well the belt is a sectioned circle, so it has an OD and an ID............73.5mm was surely wrong... should have been Cms...you are right! Darn the weekend has hit too fast! Edited February 9, 2018 by peterg123 Quote Link to comment Share on other sites More sharing options...
Troll Hunter Posted February 9, 2018 Share Posted February 9, 2018 Sounds like it's time for Happy hour! Mike Quote Link to comment Share on other sites More sharing options...
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