[s-cars] Was Serp belt woes Now PS pain
Aaron Ryba
aaronryba at yahoo.com
Sun Jan 20 13:26:46 PST 2008
I had the lock carrier/cross bar bolts in and slightly hand tight, that is why I couldn't just pull the whole hood & carrier bar up. I was able to use some pliers from the inside of the car on the end of the wire and got the hood open.
I removed the serp belt (which seems like it will be a bitch to get back in) and measured it. It looks like it is the exact correct length. Along the flat exterior it measures 1702 mm in circumference. The seat of the ribs (thickness of main portion of belt) are 2 mm in from that and the top of the ribs are another 2 mm in from that which makes a 4 mm thick belt profile from the side. Doing the math and that puts the circ. of the seat of the ribs at 1689.4 which is pretty close to the 1693 specification. I guess it depends on where the measurement is taken however it seems like the belt really hasn't stretched at all.
So I inspected the filter reservoir today and it does indeed have some very fine debris in it and all in the fluid as far as I can tell. I remembered that I had in fact replaced the reservoir filter so it started out nice and clean. In between replacing the PS pump and the high pressure hoses I did install a different bomb in my quest for better braking performance. That swap didn't seem to make much a difference. I assume at this point now pressure was normal before the swap its just that all I had to compare it to was the horrible performance before with the old pump. I evidently did have enough pressure to cause the high pressure hoses to fail if that means anything. Thinking now though I did not flush the system when I put in that other bomb so there in yet another cause for the debris in the system.
I pulled the banjo bolt with the integrated filter at the top of the PS pump that leads to the bomb (J-hose) and with that detached happily found that the PS pump rotated freely without the rotational difficulty it experiences when the J-hose is hooked up! It seems that only the few degrees in the turn that it was experiencing resistance when hooked up is the only phase of the pump rotation that pushes fluid out to the j-hose, so it was actually seeing resistance during the entire duty cycle of that part of the system. So, in addition to the fact that the pump is likely fine, this leads me to believe two things: that either there is a problem in the J-hose line (new from HOH) or with the bomb relief valve. Otherwise the bomb seems to work fine, I have adequate brake pedal pressure and the check valve is not leaking back into the reservoir.
I am also still trying to understand why the serp belt tensioner was rubbing up against the TB cover. As I mentioned in one of my first posts I found the rear of the two bolt that secure the serp tensioner mount bracket to the block was a bit loose if only by a quarter turn The clearance looks very tight down there where the TB cover and the tensioner bearing is so I am thinking it is possible the added tension from the PS pump/bomb relief valve put undo stress on the tensioner on a repeated basis and based on the eccentric loading of the tensioner bearing in line with the mount itself that additional load cause deflection of the tensioner enough to start rubbing up against the TB cover. Well, that's my theory at least. I am fairly sure I put all the pulleys and the belt on correctly because I had read that if it was done improperly the belt would come off very soon after running the engine and this condition I have has been evolving over at least 7k
miles of driving with the noise gradually getting worse. The fact that it happened gradually lends credit to the mounting bolt slowly loosening which is very likely since it was all lubed up from the hydro oil that squirted out of the failing steering rack supply high pressure hose.
Also the entire serp belt pully system looks to line up correctly and there is no excessive wobbling or misalignment one could detect with the naked eye. The exception is the scraping of the TB cover which has a fairly tight clearance anyway and still doesn't make the serp belt tensioner look out of alignment.
My next step is to detach the J hose at the bomb and check the action of the pump with the j-hose and banjo bolt attached to locate the source of the resistance in the path of the fluid. I did clean out the bolt screen although it didn't look clogged in a major way. I definitely need to flush the system clean the reservoir filter and add some clean fluid. I will reinstall my old bomb to check the function of the relief valve between the two bombs. Hopefully these things will flush out all the debris in the system fix the problem without me having to drop $200+ to fix this annoying problem .
Thanks everybody for your input here.
I probably won't get to finish this until next weekend but I will post my findings when I do.
Aaron
----- Original Message ----
From: Tom Green <trgreen at comcast.net>
To: Aaron Ryba <aaronryba at yahoo.com>
Sent: Sunday, January 20, 2008 11:56:39 AM
Subject: Re: Was Serp belt woes Now PS pain
Aaron,
Well, if the hood is locked to the lock carrier, but the lock carrier
is not secured, why won't the hood just raise with the lock carrier
attached. At least it should
come up far enough to reach in and release the latches unless it is
caught on something else.
I'm still trying to figure out why the tensioner pulley was rubbing
on the timing belt cover if everything is installed properly and the
belt is the correct size. Make
sure all the pulleys line up as well. Some can be put on backwards,
including the hydraulic pump pulley, but they won't line up.
With the screens in the bolts and the reservoir, the hose debris
can't migrate around in the system too much. It tends to stop up the
restrictors in the hoses and the screens in the bolts if there is a
lot of small stuff. Pump rebuilt is just a bunch of o-rings.
Bearing damage will most likely show as a shaft leak. Unless
you have the pump connected and fluid in the system it would be
difficult to judge one pump to another. Remember that the belt has
to be correct to operate
the pump. It may have slipped on the pulley when you demanded more
pressure in the steering.
I still say you are looking for problems that probably don't exist,
at least, not to cause the problem you have. Verify that the belt
is the correct size, that it is
installed correctly, and the things it runs are all in line and not
wobbling excessively, and don't cause the tensioner to jerk in and out.
Tom
On Jan 20, 2008, at 11:16 AM, Aaron Ryba wrote:
> Tom,
>
> Thanks for the pic, it will come in handy. The lock carrier/support
> is just laying in position without being bolted down. The hood
> release cable fasteners which attach to the lock carrier are
> missing from my vehicle so I had previously zip-tied them in with
> no problems however I had to cut them when removing the lock
> carrier so there is no longer any tension keeping that cable in
> place to allow the proper movement to actuate the dual lock
> mechanisms. Don't think it is much a problem as some research
> indicates what I thought was a solution which is just to grab a
> hold of the cable end and pull as hard as I can to take up the
> slack in the line from not being secured properly. About to try
> this in a few minutes.
>
> Good point to have the belt measured first as that is the easiest.
> I was ready to pull the PS pump today and disassemble. Although
> the cold hasn't stopped me before it would be wise to have some
> patience here. Looking at the screens in the banjo bolts and the
> filter in the reservoir are good ideas too. When I replaced the J
> hose and PS high press hose a few months ago I did replace the old
> banjo bolt because the screen was torn out. When I said I knew the
> PS pump was OK it was because I had replaced it about a year ago
> however in my last post I realized that I had to replace the two
> failing high pressure hoses (J & PS) since the pump was replaced
> and I did not flush the system. I looked at my installation and
> warranty papers from ZF and SJM which came with the remanufactured
> pump and they clearly state that the smallest amount of debris can
> cause poor life expectancy and ultimate failure and that it is
> necessary flush the entire system when any system
> component is replaced. Although most of that is verbage to cover
> themselves on warranty claims but I am sure there is some real
> truth to that.
>
> Reflecting back now, I didn't notice the tensioner noise/problems
> till after I had replaced the high pressure hoses and it is very
> possible that when they started to fail some debris could have been
> passed through the system and lodged into the pump. At the time I
> did clean the reservoir filter and install the new banjo bolt with
> the integrated screen. Perhaps the condition of those screens now
> may tell a different story.
>
> Upon recollection of installing the PS pump last year, I did have
> to turn it over by hand to prime it and had I encountered the
> resistance I am today while turning it I would most likely have
> remembered it. I don't know how easily the PS pump is supposed to
> be to turn, it just seemed to be more difficult than expected or
> remembered as about 80% of its travel was very easy to turn and the
> other 20% required a good amount of force. I could of course still
> turn it by hand by the pulley without too much difficulty, but it
> just seemed emblematic of some blockage in the pump. It also seemed
> to happen at a specific point in the rotation for whatever that is
> worth. Especially because I don't have another properly working
> pump to compare to it is hard to assess whether or not this
> difficulty to turn is THE problem.
>
> One thought of the problem with the pump (it that is the problem)
> is that there is some shred of high pressure hose jammed in the
> internals which is causing the rotational difficulty or perhaps a
> clog in a screen in the system had deprived the pump of some fluid
> and it ran dry or low for long enough to damage the bearing.
> Steering and braking assistance seem to work fine at driving RPM.
> As of late and developing concurrent with the noise issues I
> previously associates with the tensioner, I have noticed that the
> steering assistance is poor when idling like when I am parking or
> making a three point turn. Not sure if this is because of
> resistance in the pump or possible low pressure in the system due
> to a clog. Although if the rotational resistance is caused by some
> shredded hose debris would it not break down sooner than later and
> work its way out while being subjected to harder metal parts inside
> the pump? Hmmmm.
>
> Aaron
>
> ----- Original Message ----
> From: Tom Green <trgreen at comcast.net>
> To: Aaron Ryba <aaronryba at yahoo.com>
> Sent: Sunday, January 20, 2008 10:07:15 AM
> Subject: Re: Was Serp belt woes Now PS pain
>
>
> Aaron,
>
> If you have removed the lock carrier (that upper radiator support/
> cross member) where is the hood locking down? All of the catches are
> contained in that piece.
>
> I wouldn't be so quick to assess the condition of the hydraulic
> pump. Even that fine piece of German machinery has to do some work
> to produce the pressure
> that pump produces. I expect you just can't turn the pulley fast
> enough to create an even pressure output. It's 12F this morning, so
> meaningful troubleshooting
> and repair aren't possible unless you have some shelter. It's
> possible for debris to clog the little screens in the banjo bolts or
> the screen filter in the reservoir, but if the reservoir fluid looks
> clean and that screen is clean, it's not at the top of my list. The
> usual failure mode of the system is to leak.
>
> At the start you had said the pump was ok, because it had just been
> replaced. That is where I always start when there is a problem.
> What did I just do to this
> car that is making it not work? More often than I would like to
> admit, I find some problem with the installation.
>
> If you have one of the local parts places convenient to you, have
> them measure the belt. It's a 6PK 1693 belt, so it has 6 ribs and
> measures 1693mm.
> Also, just to review routing of the belt, here is a workshop manual
> illustration. Of course, it doesn't show all the stuff in your
> way. :-)
>
>
>
> If the belt checks out, and nothing else appears to be out of place,
> I would put it back together and see how things operate. Look at all
> the pulleys and the
> belt travel to ensure it is all inline and smooth. The a/c isn't
> going to be a problem for now since the clutch pulley rotates
> smoothly. The list of possible problems
> just got smaller.
>
> Tom
>
> On Jan 19, 2008, at 11:48 PM, Aaron Ryba wrote:
>
>> Thanks to everyone for the feedback on all this.
>> I finally got some time today to check the turning resistance of
>> the other ancillary pulleys and unfortunately I found what I think
>> is the culprit to my serp belt tensioner noise and poor performance
>> as the PS pump which I replaced just over a year ago has a spot in
>> it that is difficult to turn. It seems to function properly however
>> at one a specific point in rotation while turning the pump by hand
>> with the belt off it is definitely more difficult to turn.
>>
>> It is most likely due to some debris that got in the line when I
>> had my PS rack hose &/or J hose both replaces back in Sept 07. The
>> failed sequentially and I had Spokane HOH fab me up some
>> replacements which do the trick but my failure to completely flush
>> the hydro system I believe must have contributed to the PS pump
>> issue. I did notice some PS wine noise after replacing the second
>> (PS) hose but it is only noticeable from inside the car and I
>> assumed it was due to the replacement hose. Spokane did ensure me
>> that they kept the dampener piece as part of the new hose however I
>> still had the newly developed noise so I was unsure what had
>> happened. I have nothing but good to say about Spokane, they had
>> great turnaround, a clean product for cheap and great customer
>> service.
>>
>> I am doing some research now to find out if I can rebuild the pump
>> instead of forking out another $366 or whatever for another rebuilt
>> pump. Helpful comments appreciated.
>>
>> Those of you who said the belt didn't stretch are most likely
>> correct here, and I assume the tensioner is probably fine, just
>> under too much stress from the pump. The AC seemed to turn over
>> fine, however it was too cold to engage the clutch and check it
>> that way. Also the belt is a Meyle product.
>>
>> To make things worse, as I was wrapping up my recon today on the S6
>> while it was sleeting out and I accidentally shut the hood all the
>> way and now can't pop it from the inside because I had removed the
>> radiator support/cross member and therefor the stays for the hood
>> cable. My inclination is to try to disconnect the cable at the
>> handle end inside the car and pull as far as I can hopping i will
>> get enough tension to pop the hood. Any suggestions?
>>
>> Aaron Ryba
>> 95 S6
>>
>>
>>
>>
>>
>>
>
>
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>
>
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