Power steering

[redhed]

I have just replaced my power steering hose for the second time in a month. I used the official BMW high pressure hoses that are called for on my 735i. Could the problem perhaps be the power steering pump? (I'm thinking that maybe it's putting out too much pressure which is what is causing the hoses to burst). If so, anyone have any idea about how much it will cost to get a new pump? If you think it may be something other than the pump, what would you suggest it may be?

[jeffreyb4me]

Your 735i has several 'power steering' hoses and it's not clear if you replaced the same one twice or [as I hope] two seoerate ones. Which ones have you replaced ? ? ?
these hoses do become porious over time and require replacement.
I've never seen a 'pressure relief' valve stick in any 'ZF' pump or cause this kind of failure.......jeffb.

[redhed]

It's the same hose. It's the high pressure hose that leads from the power steering pump. (It's the one with the fittings at each end of the hose that sits right on top of the engine. The main one you can see).

[jeffreyb4me]

If you replaced it yourself, were you careful to postion it away from the engine and related brackets one it's way to the gearbox? This hose moves under pressure a little and could have chaffed against something. It's very unusual to see a 'Factory BMW' P/S hose fail so quickly though I have seen 'aftermarket' replacements fail due to poor fitment because of poor pipe bending and 'cheap' construction....puzzling...............jeffb.

[redhed]

Well, the second hose was a BMW hose that was taken off of the exact same model and year car as mine in a junkyard. Maybe that's why it busted, but I swear it was in perfect shape. It IS puzzling. My nephew (who is a professional mechanic) replaced it for me, so I'm sure it was done properly. He's coming this weekend to look at it, so we will see.

[IdahoRocks]

I've been trying for the last several hours to thread the M14 banjo bolt to reattach the hydraulic line on the the power steering box on my '93 740iL. I believe I have found a new level of personal hell. There is very little roof to manuever my hand to get the washers, bolt, and fitting to properly line up with the hole, and even when I occasionally do, the bolt is just far enough out of allignment that it won't thread by hand. Any hints on doing this that doesn't involve lifting the engine?

[jeffreyb4me]

Yes......if you haven't demounted the pump from the engine, do so, it gives you just a little more play. Also, removing the oil filter return pipe from the block gives you a little more room. I do these all time and smiles are rare....try walking away for a little bit, relax then go back, and it will suddenly go right together.

[IdahoRocks]

I'm talking about the two hydraulic lines going into the top of the steering gear box directly under the exhaust manifold. I managed to remove the ABS unit to get better clearance but the s shaped bends in the hydraulic line I'm trying to replace keep getting in the way of the fitting with the banjo bolt. Just putting my hand down there puts pressure on the line that contributes to the allignment problems in the fitting. I think if I jack up the engine a few inches I can easily get it. Too bad I don't have an engine jack.

[IdahoRocks]

One full day devoted the bolt and it finally threaded!!! My finger tips hurt. If any of those hoses even tries to leak......

[redhed]

I said that I would let you guys know what the problem turned out to be, so here it is:

My nephew said that the problem is in the power steering fluid system. He said that there is a blockage in the system somewhere that is not allowing the fluid to flow freely. There is very little fluid flowing through the return. What is happening is that because it's a high pressure system, but isn't flowing freely, the fluid is building up and building up and and the pressure forces it to break through at the weakest point in the system, which is the hose connection, which is why the hoses keep busying right where they connect to the metal fitting. He will un-block the system and replace the hose and that should fix it.

It's good to know that it's not something major, thank goodness!