No announcement yet.

Renew heater hoses - not as bad as it sounds

  • Filter
  • Time
  • Show
Clear All
new posts

  • Renew heater hoses - not as bad as it sounds

    After a Facebook reply I decided to add it here as well so I don't have to repeat it again.

    Replacement of heater hoses

    You need to clear the decks first, times are budgets, allow enough time !

    Bonnet Area ( 10 minutes )

    Remove the middle card insert covering the fuel tank and remove it, don't be tempted to leave it folded over, you don't want it to get wet (just in case)

    Remove both side inserts covering the wheel arches, be careful in case the plastic rivets are still holding these in at the top of the wings or you will tear them.

    You should be be able to see the heater hoses entering the drivers side and returning to the passenger side.

    SOME CARS ARE DIFFERENT ! Early cars have a double skin in the areas where the hoses come from the cab so they appear to disapear inside something, don't worry they are just as easy to access as the ones without the double skin.

    Interior passenger and drivers footwell / inner wheel tubs ( 20 minutes doing it carefully).

    The hoses you seen in the bonnet area enter the car head down the outside of the joint between the wheel tub and te A pillar, enter a small curved section at floor which allows entry to the inner box section/sill

    Any carpet that has been stuck down will need peeled back, on cars that have had carpets and underlay stuck down this can be brutal and I often find they have been glued to the heater hoses and of course trying to pull hoses through when they have sticky stuff and debris attached, no can do, just an invite for more hassle.

    Drivers side be careful of the wiring harness and capillary oil pressure feed on sports and chamois, if you decide to attack anything glued down with a knife,

    Your heater hose is now exposed to the front of the box channel/inner sill on both sides, watch the wiring harness and pipe on drivers side !

    Front Seats ( 15 minutes ).

    My own preference as a largish fellow is to remove the seats, 4 bolts a side and that's them clear, you will be ferreting about in the back so the front seats will get in the way especially if you are working on your own.

    It is better with two people (more later) as it makes the work SO much easier.

    Rear Seats ( 5 minutes ).

    Lower the rear fold seat to protect the rear lower squab.

    Rear side panels and trim capping panels if fitted ( 15 minutes per side )

    The side trim panels if not bare metal are usually removed by a couple of cross head capped screws, dont lose the screws or caps on removal.

    The side panels, you will need to remove the seat belt retainer and remove any retaining screws, as these tend to warp before trying to remove it from the clips, make sure someone has not added more self tapping screws than factory.

    The panel will pull free, some clips might have a little rust but try and get behind and pry as the hard board the vinyl is wrapped around can be pretty rotten and any clips might get pulled free.

    NOTE - Insulation if it is fitted HATES getting wet, remove the "stuffing" from anywhere that might get wet.

    Last thing, the bottom of the rear side storage pockets needs removed, this just lifts out.

    Point a lamp down their and you will see the hose (and on drivers side the wiring harness and oil pressure gauge line)

    Engine Bay ( 30 minutes )

    OK, time to get busy !

    Remove radiator cap and drain radiator. Use clean container to save the coolant for re-use.

    Remove the left hand hose that comes from the rear wing from the 3 way valve on a standard imp or from the radiator in the case of a MK 1 (rare)

    Remove the right hand hose that enters the rear wing from the engine.

    Let what will drain, drain, there is still a lot of fluid in these hoses !

    Drain the hoses

    Two ways. Both require heater set to hot to open the valve

    Use an airline - Add air pressure to the hose and blow the coolant out

    Remember if its coolant it wont "evaporate" easy. I have opened cars hoses been sitting for 20 years and still had coolant in there, it was horrid and rank but still there.

    In lieu of an airline use a very long garden hose, unwind it and lift the hose along its length with both ends open to "empty it" you now have a lot of air, attach to hose on car, connect to tap and turn tap on, air should push coolant out before water ends up refilling it.

    It is important to drain the fluid.

    Hose Removal ( 15 minutes per side )

    My preferred method as the bend at the bottom of the rear storage pockets can be a pain and there is no ned to save the old one.


    I cut the hose at the kink under the rear side storage pockets and push the hose back into the inner wing

    Then I cut the hose in the front area inside the car as the hose goes through the bulkhead to the bonnet area. DRIVERS SIDE WATCH THE WIRING LOOM and pressure pipe !

    The hose is now in 3 pieces either side.

    Bonnet to passenger / driver side area.

    Remove hose from heater matrix or heater valve, then simply pull through into bonnet area and discard. Early cars with the double skin may require manipulation to pull out but nothing substantial.


    Box channel / inner sill box section length,

    Pull through from front of of section at A Pillar, take your time on the drivers side, watch that harness and pipe on drivers side!

    Rear inner wing section

    Lift the inner wing section of the hose from the bend area at bottom of door pocket up into the space above, remove it from any tangs that retain it, there is sometimes tangs bent over to hold the hose in place.

    You should then be able to pull the remaining section into the car from the engine bay.
    This is substantially easier if someone pushes the hose into the inner wing from the engine bay side as it tends to chaff on the grommet.

    WATCH THE DRIVERS SIDE LOOM AND PIPE - cant stress that strongly enough as you may have noticed.

    That's the old one out.

    Refit hose ( about 30 minutes per side )

    Again my own preference working from one whole length of GOOD QUALITY thick outer 5/8" ID hose.

    A top tip is lubrication, anything to stop rubber doing what it does best and cause friction !

    But a better top tip with next to no mess came from Mike Dent who has changed more than a few hoses in his day, far more than me, clean down the hose with brake cleaner first, it makes the outer shiny and easier to push through. Top Tip Mike moose549

    The hose enters the front box channel/inner sill via a curved area, you can feed the hose down here, around the curve using the cut recess to guide it into the channel and push this through till it exits the box channel under the rear storage pocket.

    Now this is where it gets funky and two people are better than one, otherwise you end up back and forth at each end of the channel.

    While someone puts mild pressure to push the hose into the front of the box channel, you can gently inch the hose through the bend into the rear inner wing area and up into the easier to get to inner wing space, while the assistant feeds in at the front end you can keep feeding through the S bend with little force and then into the rear inner wing area.

    You can reach the grommet by hand easily from the aperture into the rear inner wing in rear storage area behind the wheel tub so once you have enough hose in, pop it into the engine bay.

    Once you have enough in the engine bay, measure up what is needed and cut, feed into bonnet area, trim and fit to heater matrix or heater valve.

    Drivers side is same, BE CAREFUL of the wiring loom and gauge pipe.

    Reverse order for refitting.

    Hope that helps and the time taken to do the waffling will save you time in doing the job
    Last edited by John A. Ross; 24th April 2020, 09:23 PM.
    / John

  • #2
    Don't just clean the outside a little spray through the rear pockets as you are feeding it through helps it slide. Also as you feed it through grommets or any other tight points. Don't go daft with it and wash all your waxoyl out it does evaporate quickly and using a can of it with a straw attachment will keep 90% of it on the rubber hose it won't damage proper paint, it has no lasting effect on the hose. Just think about where you are spring it as it does make the rubber slippy so it can be hard to grip the pipe to pull or push.


    • #3
      The only problem l encountered was the off side pipe kinking it round the bends under rear seat , the near side just basically fell in the right position , didn't need any persuasion but off side just kept on wanting to go wrong side of whatever it was hitting , put it down to the use of which hand to do the job with, if you see what l mean , l was loading it while standing outside the car leaning in through window aperture, that probably makes it easier for that section.


      • #4
        I have sme problem Bob Petowner working with one side is much harder, on DDG 220C I did cheat a little though as complete restoration was not the goal.

        Click image for larger version

Name:	PIC-09ddd479.jpg
Views:	20
Size:	165.0 KB
ID:	8156

        The small hole in the rear side storage pocket area is so i can bring the hose up through the back of the side pockets and then in the arch, gets rid of the kink completely

        Not much use now but well done getting it through !

        / John