Crimp type hose clamps - cut them off?

[Evan Bottcher]

Hi folks, forgive the ignorant question that follows...

I was going to replace the MAF sensor on the 159, the air hoses have factory hose clamps that appear to have a crimp in them.  Am I right in assuming these are one-use-only and I should cut them off and replace with a regular screw-type hose clamp?

If they're not re-usable, anybody have any idea why these type of clamps would be fitted?

[Jekyll and Hyde]

They're definitely reusable.  Correct tool shown in link below.  Note that all the pictures showing them 'in operation' are for refitting the clamp, in removal the pliers are used the other way around, so that the ramp on the big jaw pushes the 'latch' up on the hose clamp.

http://www.ebay.com.au/itm/HOSE-CLIP-CLAMP-PLIERS-CLIC-and-Clic-R-type-TYPES-CLIC-AND-CLIC-R-/170810795865#vi-content

The work around, if you can't get your hands on the proper tool before you get to doing the job, is to flick the 'latch' part of the hose clamp up with a flat blade screwdriver to undo.  Refit by using side cutters with a lot of care - needs to be side cutters, as the jaw is thin enough to allow the 'latch' to click back into place.

[Neil Choi]

I presume crimp-on hose clamps is just a time saving manufacturing process. 

Hence when replacing, you can use the usual screw-on hose clamps as you can take your time turning the screw driver ever so quickly or slowly while sipping your gin and tonic.

[Neil Choi]

Perhaps I am incorrect as J&H explains!!!

[Steve S]

Fiat/Lancia/Alfa have been using these style clips for over 20 years! These factory clips are easy to use and fast if you have that tool. They are also very tidy and retain the original look. I would not replace if possible.

[Evan Bottcher]

Okey! Glad I asked - for some reason googling was not providing me with much help. Thanks!

[colcol]

They are put there by the factory as it is evidence of any tampering during the warranty period, on my 156 they are all being replaced by tridon stainless steel worm type clamps on the coolant hoses and the air intake hoses.
When i do the annual, replace the thermostat on the 156, instead of stuffing around with one time use only clamps, i just undo the clamps, all the intake hoses come off and i have room to work.
Also, when i take out my air cleaner element, and shake the dust out of it, i just undo the worm clamps.
I f you blow a coolant hose of any sort and go to a service station and get a generic coolant hose to get you home, ask if they have a special tool for uncrimping hoses, and see what they say.
I will go to the boot of my 156 and undo it with a Alfa Romeo supplied slot screwdriver in the toolkit.
The repair guys in a van hate these stupid crimp hoses, as they have to cut them off, before replacing them with a proper hose clamp, Colin.

[Evan Bottcher]

I borrowed the correct pliers from my favourite mechanic friends, and it took 2.5 seconds to get them off and back on again.  I might buy one of those tools, for very occasional use...

Diverting the topic, I used the pliers to remove the MAF sensor on the 159 2.4 JTDm.  It's been a bit lazy with power, and stuttering a bit on partial throttle.  The lack of power seemed to come and go a bit, possibly with ambient temperature.  So many wonderful opinions on the internet, but a common theme of the MAF sensor potentially causing a gradual loss of power without triggering any ECU errors, and also causing the stumbly/stuttering on partial throttle (MAF and MAP sensors are input to the fuel map and operation of the EGR).  After almost 130,000km it seems like a reasonable thing to just change as a matter of course anyway.

Bah - I received the wrong part from the UK.  Incorrect size, different part #.  Attached photo original is on the left, replacement is on the right.  My fault for ripping off the local industry, and not checking the part # before ordering.

So I cleaned the existing MAF instead, using non-residue contact cleaner, and refitted.  Test drive showed a significant difference!  With almost all of the stumble on partial throttle gone, and it feels (butt dyno) like heaps of grunt has returned.  Ripper!

I think I'll acquire the correct MAF and fit to see if it makes any further difference.  FWIW if you have one of these diesels it's also worth cleaning the MAP sensor occasionally too, I've done it a couple of times now as it's in the intake manifold it cops a bit of soot via the EGR.  A single bolt and it pulls out and easy to clean, seems to take out a flat spot that develops down low.

Anyway, cool story bro.

[colcol]

I have seen a few recalls on cars where they have caught fire due to fuel leaking out of fuel lines, because the hose clamp was recrimped, rather than replaced with a new one, the recall for the cars involved driving down to the dealer to have your crimped hose replaced by a screw worm drive type, they very rarely fail and when they do, its when you are doing them up or in the case of a mild steel one, they are rusted up, and then they have to be cut off,.....speaking of rust, i like the Alfa Romeo 'ROMABLOCK' hose clamps as they don't bite into the hose and take big bites out of it, they just tighten the hose up, and isn't that what you want, Colin.

[Steve S]

A high pressure fuel hose is a different story to an inlet hose. It shouldn't even have a removable hose clamp from the factory

[Nikola78]

Need a help on where the MAF sensor is located on 2.4 jtdm..much appreciated!

[Evan Bottcher]

The MAF (air flow) sensor is located in-line with the air hose immediately after the air cleaner, facing the front of the engine bay it's at the front left.  In this ePer diagram, it's numbered '2':

eper.fiatforum.com - showing air cleaner and hoses

The MAP (manifold pressure) sensor is bolted into the rear of the intake manifold, at the rear left of the head (facing the front of the engine).  Shown here in this ePer diagram as number '4':

eper.fiatforum.com - showing intake manifold with MAP sensor

On our car, cleaning both has had a brilliant effect.  First time I cleaned the MAP sensor it was completely caked, you couldn't even see the plastic cage that the sensor sits behind.  I've cleaned it once with MAF cleaner and once with regular electrical contact cleaner (which I suspect is the same thing).

The MAF sensor I've read lots of advice on how to do this, and sounds like it isn't always effective.  I used electrical contact cleaner, with the little tube attached and poked through the front plastic screen to get right into the sensor.  Just a squirt, drain, shake dry, repeat a few times, seems to have helped enormously.

Cleaning the MAF has 98% eliminated the stutter/stumble we were getting on partial throttle.  Slightly educated by morons on the internet, my speculation is that the MAF isn't effective at measuring the additional airflow at partial throttle and low boost.  The ECU uses input from the MAF and MAP to decide when to open the EGR valve, and with a fluctuating signal from the MAF is opening and closing the EGR causing the stutter.  Also filling the intake with dirty exhaust gas :/  Anyone confirm or refute this idea?

Has anyone on here had an ECU flash to disable the EGR?  You can PM me if you're shy about this...

[Nikola78]

Thanks heaps Evan,cleaning MAFs gonna be my next mission..