Vacuum boost hose routing

drhodgie

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My 72 CS brakes real hard. I took it to two different shops and they could not solve the problem. SFDon came over to see my car and spotted the problem in 10 seconds. He called my attention to the vacuum boost hose that was almost kinked closed at the top.

I assumed it was easy fix to get the correct hose and install. But I am not sure of the correct routing.

I am including some pix of the hose. Thanks
 

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HB Chris

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Should not be kinked like that, it comes straight out and curves in a loop nearer the booster. There is a clip to hold the hose on the inside master cylinder attaching nut. Looking at booster, hose starts at 12:00 and goes counterclockwise to 9:00 (clip), 6:00 and stops at 3:00.
 

drhodgie

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Turns out the hose was too short. Just ordered 1 meter of new hose and with new routing which should solve the braking problem. Thanks
 

deQuincey

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IMHO your are using a wrong type of hose
it seems that you are using a conventional rubberhose with textile coating
the hose that should be used in this case must support vacuum, so it must be the type of hose that has a reinforcement inside, usually a mesh of steel wires
this type of hose supports vaccum and thus it can not be bent or clogged by a sharp radius
try to find the appropriate hose !
 

Stevehose

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I have braided cloth covered vacuum hose with wires inside for this so his could be same - available from Belmetric.


IMHO your are using a wrong type of hose
it seems that you are using a conventional rubberhose with textile coating
the hose that should be used in this case must support vacuum, so it must be the type of hose that has a reinforcement inside, usually a mesh of steel wires
this type of hose supports vaccum and thus it can not be bent or clogged by a sharp radius
try to find the appropriate hose !
 

drhodgie

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Booster drawing

Just installed the now reinforced hose (Belmetric). But I could not perform the routing you suggested. Do you think my booster was installed upside down (see drawing)?

Also a new problem just cropped up. It took 2 hands and a real hard pull to remove the dipstick. I am enclosing pix of of the stick (with measurements). Looks like the mechanic hand ground 2 markers (low and high?) at the tip. I have a feeling that I have the wrong dipstick. Also the top is painted red. Maybe the wrong tube? Any thoughts?

Thanks
John
 

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deQuincey

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your booster is not upside down, butthe plastic connection tube is
i mean it is a black plastic tube, and it is fixed by introducing and turning it until a "clack" sound is produced
but you can fix it in three different positions
the one that ends facong up is the roght one
i men your hose then will come up vertical and you can do the routing with the correct rigid hose
is it clear ? i am afraif i can not post pics now to explain this better
 

Stevehose

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My dipstick measures 16 3/4" and I have an original engine - is yours original or from a later model? Mine's painted yellow.

Also a new problem just cropped up. It took 2 hands and a real hard pull to remove the dipstick. I am enclosing pix of of the stick (with measurements). Looks like the mechanic hand ground 2 markers (low and high?) at the tip. I have a feeling that I have the wrong dipstick. Also the top is painted red. Maybe the wrong tube? Any thoughts?

Thanks
John
 

61porsche

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orientation up



The dipstick tube measurement is listed on the part diagram.

As Steve stated, any number of factors could result in a different part.

I agree yours looks suspect. But wether available new now is red or yellow is unknown to me as parts can be superceeded. Paint it, if that's your goal. If it's red, it may be the fingerpull version. Mine is the hook type which faces toward the radiator.

If one were say at the time of an oil change quantify the new units of oil put in, measure from the top of the tube and compare the marks below the tube to the level, it may give you some comfort level.

Assuming the car has been running for sometime, someone did something at least in the ballpark; even if we can now say it could have been done differently or authentic. Mine is cut deliberately by a previous owner, connected by a short hose and clamps. I would rather see that than a bent up piece that wiped the oil off. But I know the engine has been freshened.

Be careful if you're thinking about a new tube. If it doesn't come out easily, you're going to drive it upwards out of the oil pain area easy if the engine's out on a stand. No so easy if not depending on your skillset, raw determination, or you've got a stash of kruggerands around for just such an occasion.

Happy trails ( Blue as Murray would remind us all)
 

HB Chris

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drhodgie

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your booster is not upside down, butthe plastic connection tube is
i mean it is a black plastic tube, and it is fixed by introducing and turning it until a "clack" sound is produced
but you can fix it in three different positions
the one that ends facong up is the roght one
i men your hose then will come up vertical and you can do the routing with the correct rigid hose
is it clear ? i am afraif i can not post pics now to explain this better
I can move the tube about 35 degrees to the left or right (until it stops). I have been reluctant to force it for fear of breaking it. Should I put an open end wrench on the base and turn it until it faces up? It will not break????
 

drhodgie

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My dipstick is 16". What concerns me is that with about 1/2" to go the dipstick hits something solid in the bottom of the crankcase. I could force it but I think that is how it got stuck in the first place.
I am thinking that if the dipstick is the proper length then the tube maybe wrong too short allowing it to go too deep. Do you know is the proper dipstick tube length?
 

61porsche

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Dipstick

tube is 300 mm. That of course includes what is inside the block. A piece of wire with a small hook , stuck down, and marked for measurement would do.

Can you turn the dipstick to get to its final position? IIRC that's what I do.

No, pls. don't force the hose fitting on the booster. Leave the hose extra long, create a loop about the size of your fist, then get the end near the manifold before final trimming to length. That's what I did only because I like things out of the way.
 

drhodgie

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2 Length DipSticks

Turns out there are 2 dip sticks. Red (mine) and yellow.
The way I am reading this is that if you change the oil pump you have to use a shorter dipstick. My engine was rebuilt and I would not be surprised if the mechanic change the oil pump (and not the dipstick)

Here are the manual pages. What do you think??

http://www.e9-driven.com/Public/Library/BMW-E9-Manual/pages/en/11410000.html
 

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deQuincey

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I can move the tube about 35 degrees to the left or right (until it stops). I have been reluctant to force it for fear of breaking it. Should I put an open end wrench on the base and turn it until it faces up? It will not break????

do not force it!
when you move anticlockwise until a stop then you can pull it out on that position
do that and then insert in the next position, and then turn it clockwise to fix it
you can start it in three different positions, probably you will understand tgis when you pull it out
regards
 

jmackro

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do not force it! when you move anticlockwise until a stop then you can pull it out on that position do that and then insert in the next position, and then turn it clockwise to fix it you can start it in three different positions, probably you will understand tgis when you pull it out

That's right. This is what is commonly referred to as a "bayonette fitting" - it works like a gas cap. It is NOT a tapered thread fitting - that is you can't just apply more torque to get it to move a little more clockwise.
 
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