Rear Calliper Repair

NB: - If parts are really rusty or shaft seal has ripped, the repair may not work/last very long.

1. Mount calliper in vice.
2. Wind the piston out with a 10mm hex-key or appropriate tool in a reversing drill.
3. Remove the circlip from the bottom of the calliper using RS components circlip pliers and 2.5mm ground Allen keys to get the reach. (You may need a mag-lite as well).
4.Wind on jacking tool enough to hold the pliers against the face of the bore. (Jacking tool is the core of a spare adjuster). Then turn it clockwise with pliers under the lip to pull out the threaded bar and O-ring. (mole grips can be used if soft aluminium is wound around the thread – runs a risk of bore damage though)
5. Remove the 6mm bar from the bottom of the bore with pin nose pliers (if it’s not stuck to the bottom of the threaded bar).
6. Pull the lever out, file the rust from the bar and dig the rust and debris out of the bore. Clean as best as possible. An airline is useful.
7. Put back the lever/bar with loads of grease.
8. Insert the 6mm bar, pointing vertically upwards.
9. Clean the end of the threaded bar which supports the O-ring with wet and dry, and then polish with Autosol.
10. Put the bar back in the bore.
11. Push O-ring into groove using a rounded screwdriver or dentists probe.
12. Put cap back in, punching with 2 diagonally opposed screwdrivers.
13. Put circlip back in using just a screwdriver.
14. Reassemble the piston.

16v should be easier if bigger bores

Don’t forget the new trick when fitting pads of winding the pistons OUT on the thread to suit pads, saves having to pump the brake pedal dozens of times and avoids the piston getting stuck at base of bore resulting in no handbrake action at all.

Currently I have 4 callipers still operating fault free on 3 different Thema Turbos.

As any good editor should, I have tried this out before printing the article. It works, it’s tricky and I don’t recommend doing it within earshot of your mother! The o-ring at the bottom of the calliper is enough to make a Bishop swear! I found it easier to hold the spring and cap in place with a G-cramp while I fitted the circlip.

ABS Sensors

Here is a snippet of information that may be useful to all you Thema owners with flashing warning lights. Some time ago, for no apparent reason, the abs warning lamp started coming on in my S1 turbo. This was usually after moving off and attaining a speed over 20 mph. This indicated a fault with a sensor however the peculiar aspect of it all was that the warning light did not always come on. Sometimes it stayed off for days and would then reappear for weeks at a time. Inevitably although I always intended to get to the root of the problem I never did, just suffered the warning light.

Then on a trip to the south of France I noticed that there was a degree of wheel vibration at speeds in excess of 90mph. So before my return I went to a tyre shop and asked them to check the wheel balance. The fitter then noticed on spinning up the offside front wheel that the tyre, although in otherwise good condition, had developed a flat spot and was running therefore in an elliptical motion. This meant of course that he could not balance the vibration out and the recourse was a new tyre. This was duly fitted and lo and behold no abs warning lamp! And this has remained the case ever since. I can only assume that because of the flat spot on the tyre it was telling the sensor that the wheel was momentarily locking up and therefore as the brakes had not been applied assumed that the system had gone down and was switching it out. Anyway whatever the technicalities the problem is now resolved. So whatever you do check your tyres first!!

Door Rattles

My Dedra has only got 50000 miles on the clock, and is very tight and rattle-free - except for the driver's door, which has an irritating squeak - or did, until I worked out what it was! It is the rubber of the window surround, chafing against the glass! If you hit the window knob for a split second (not enough to open it, but enough to take the pressure off the rubber surround so that the glass doesn't chafe any more) it stops completely!

This may be something that only affects my car, but I suspect it isn't – the Autocar road tests of the car mention rattly doors, and neither of my doors have any other rattles (the passenger door doesn't even have that one) – I wonder if that was what the problem was on their cars??

CV Joints

Recently I had a loud clicking sound coming from my front nearside wheel. I immediately got my local garage to have a look for me thinking I had a CV joint on the way out.

On inspection they found the outer joint o.k. but the inner CV joint bone dry, the boot was not split and they thought that this may be down to it being so close to the gearbox and the heat generated by it, so if any other Thema owners have a similar problem, check out both inner and outer CV joints.

Thema Ventilation System

My first tip applies to Series 1 Air Conditioning units so it might not apply to too many owners, but I believe all electronically controlled heater units have some form of self diagnostic system provided you know which sequence of key presses activates it.

On the S1 A/C control unit the self diagnostics are triggered by pressing the “Auto” and “Vent” buttons simultaneously. This sets the unit into a 3 minute test cycle. When complete the display will show how many faults have been found. To identify the faults press “Vent” and a 2 character code will appear. The codes correspond to faults as follows:

1C-1U internal temp sensor,
2C-2U external temp sensor,
3C-3U blend sensor,
5C-5U blend flap motor,
6C-6U air flap motor,
7C-7U air intake flap motor,
9C-9U compressor relay,
AC-AU electric speed regulator

Disregard 4C-4U and 8C-8U (if shown)

Series 2 – “Automatic Heating Systems”:

Some faults affecting the non – A/C “Automatic Heating System” can be detected without the diagnostic check system. As a general rule the control units are very seldom the cause of faults.

Thema Gear Linkage:

Sloppiness or Rubberiness in the gear change is something that can creep up insidiously and it’s not until you drive another Thema that you realise how good the gear change should be.

If the gearstick can be freely stirred when in gear and the self centering is next to non-existent then you most likely have worn bushes. These can either be at the gearbox end or at the bush at the base of the gearstick.

In my case I found the greatest improvement when the bush at the base of the gearstick was replaced, however, this is a far more fiddly operation to replace.

If with the gear stick in gear it is still possible to move the gearstick, but there seems to be a “rubbery” resistance to the movement, then you probably have a partially cracked linkage rod to the gearbox. This rod is prone to cracking at its forward end where it is flattened out for bolting on to the short rod that enters the gearbox. See the picture.

If you suspect this is a problem then you can usually feel the crack in the rod. Put the car in gear and then push the gearstick as far as it can go in each direction. Whilst the gearstick is in each of the extreme positions, run a finger along the flattened part of the rod and you will feel the crack in the metal. That’s the easy bit…

To remove the linkage rod for replacement or welding you will have to follow these steps:

1) Jack up the front end of the car so that you can get access to remove the two bolts that connect the flattened end of the rod to the gearbox selector rod. These bolts are from memory 13mm and you will need to get a spanner/socket on to both ends to prevent them spinning.

2) Remove the centre console to get access to the base of the gearstick. I don’t want to insult your intelligence, but for the inexperienced the console is held in place by:

• 2 screws which are hidden beneath the panel for rear cigarette lighter
• 2 screws beneath the front ashtray
• 1 bolt (10mm?) that attaches the console to a brass plate beneath the stereo.

3) The handbrake will need to be slightly loosened as well to allow it to go sufficiently high for clearance when removing the console. It should also be mentioned that the driver’s chair will also need to be reclined to get the armrest out of the way.

4) With the console out of the way it will be possible, just, to get access to the bolt that goes through the base of the gearstick. This bolt is held in place by a 10mm nut on the LHS and has an 18mm head on the RHS. It can be removed with patience without further removing the inner plastic sections of the console, but be prepared to get your fingers nicked.

5) When removing the bolt watch out for the 2 black plastic sleeves that are inserted into the hole at the base of the gearstick. These plastic hole liners take up slack and can have a significant effect on the tightness of the change. Replacing these liners may cure your problem, but if the rod is cracked as in the picture then more dismantling is required.

6) It is relatively easy to manoeuvre the linkage rod backwards along the centre console and past the handbrake, but it will be necessary to go under the car again to slip the rubber boot off the front end of the rod.

7) Replacing the linkage rod is (as they say in the Haynes Manuals) just a straightforward reversal of the above, but be sure to feed the rubber boot carefully over the end of the linkage rod to avoid tearing it.

Fuel Hoses

I picked up this info from Integrale ownership, but it can affect the Thema/Dedra cars as well and will probably be most noticeable on the turbo models.

It is a problem with the in-tank fuel hoses fitted to the fuel pump which are common on these cars. These can go porous and leak with age and high mileage. The symptoms will be a loss of fuel pressure, which will be most noticeable at high rpm and full throttle when the car will tend to 'back off' under power.

The engine should be protected by the knock sensor which will retard the ignition if detonation occurs due to subsequent lean running but this will only be able to do so much. The hoses are inside the fuel tank meaning any leaks will just go back into the main tank supply and not be visible.

Fuel pump viewed from top. Large plastic nut needs loosening with a hammer and drift.

Replacement means disconnecting the fuel lines and removing the pump to get at them, plus it needs to be high pressure all-neoprene fuel hose as it is submerged in the fuel. Normal fuel hose is neoprene with a rubber outer which the fuel will attack.

This photo shows the new pipes fitted. Note the crimped clips which are much better than jubilee clips and come with the kit.

Barry Waterhouse supplies a kit of parts to sort this, including good quality 360deg clips for about £8 so it's not an expensive repair even if it’s a pain to do. It is also worth getting some new o-rings for the fuel line to tank fittings as these can leak once disturbed as well.

One thing worth adding is that the o-rings on the fuel lines also need to be special material suitable for fuel.

I was looking in a kit of o-rings at work for some and phoned the manufacturer to find out if they were suitable. The answer was no, because they were made of medium nitrile and would need to be either high nitrile or viton material.

Worth adding this to the tip as I nearly fitted some to mine and once they melt with the fuel you would have a 6 bar petrol fountain in the car – not nice, especially in the Integrale as its under the rear passenger seat.

I was wary of this because I recently changed a split fuel tank breather hose and despite telling the guy in Halfords what it was for he sold me ordinary heater hose which worked for 24 hrs and then I found some sticky goo running down the back of the tank which was the hose starting to melt!

Another recent fault which I found on both my cars was the turbo recirculation valve. This looks fine from the outside but both mine had split diaphragms inside and a spare from my old 8v Thema was duff too. Testing is simple - the small pipe on top should hold vacuum and pressure if the diaphragm is ok. I used a vacuum pump to check mine, but I would think a foot pump will do with a suitable adapter. This part will see anything from about 25 inHg vacuum to 15psi pressure on the car so needs to be in good condition.

A standard recirculation valve from an 8V Thema.

Its purpose is to let the pressure off the turbo when suddenly shutting the throttle, so reducing the risk of unnecessarywear or damage. With the diaphragm split it simply doesn't work. I managed to get a second hand one off a mate with a Fiat Coupe who had replaced it with a more expensive piston type valve which is more reliable. He was a bit fed up when there was no difference in performance but happy enough when I gave him £20 for the old one which was in perfect condition. This will eventually go on my Thema once I get a piston type one for the Integrale.

16v i.e. Cold Running

If you have a Series 2 Thema 16v i.e. with the annoying problem during warm up of the engine stalling abruptly when it is needed to idle, then here's a solution that I've found works perfectly.

I have had problems with the engine stalling when warming up for the last 6 years and I've tried all of the following to cure it:

• Replaced air flow meter
• Replaced coolant temperature sensor
• Replaced Air Bypass Valve
• Thoroughly checked for air leaks

In the end the solution was incredibly simple. On the back of the air bypass valve there is a small nut (6mm). This nut allows the opening of the valve to be adjusted. If the nut is loosened and then moved outwards from the centreline of the air bypass valve it opens the valve wider. This gives a higher idle speed when the engine is cold and effectively keeps the choke on for longer during warm up.

There is only a small amount of travel in the adjustment, but the difference it makes to rpm when cold can be significant.

For those that don't know, the Air Bypass Valve is mounted to the right of the cam covers on top of the thermostat housing. It will appear to be a metal disc with a rubber pipe attached either sideof the top half of the disc.

I hope this helps someone else out there. It’s certainly made a world of difference to the drivability of my car when cold.

Dead Dedras Revived!

Does your Dedra cut out occasionally when cold? The following might be the answer.

For sometime now our Dedra would occasionally cut out when cold usually at a junction or other inopportune moment. I slowly worked through all the suggested possibilities including cleaning all the earth connections but to no avail. Due toits intermittent nature the faultwas becoming quite tiresome, however, one particular morning the car refused to start, at last a chance to find the problem.

When I opened the bonnet I noticed that the HT lead from the coil was at a strange angle where it leaves the coil and on inspection almost everything under the rubber cap had eroded. After removing all the burnt carbon string and insulation I could see that the top `bakelite` mouldinghad also gone although the brass contact was OK, so after fitting a new lead the car ran fine. As I didn't have a spare coil I wondered if I had finally cured the problem or if it wouldreturn. After only a few days the car cut out but there was no erosion, I was very disappointed.

I exchanged a few e-mails with Brian Hilton and the conclusion was that the coil or more precisely the power pack fitted to it could be to blame, now for a shock. None of the local `factors could help with a new coil so it had to be a Lancia/Fiat part, a new coil complete was a staggering £144 plus VAT! Brian suggested that John Brain or Dave Abbett might have a s/h one, both did so I got Dave to pop one in the post, £40 inc.post. Expensive compared to the conventional Lucas part but I was unlikely to prove the fault without it. The transformation was amazing not only had the cutting out disappeared but the engine was so much more smoother and the car so much nicer to drive.

After telling the tale to a friend who works for a Renault/Nissan dealership he recalled that `spark` erosionlike thisis not uncommon on Renault and Peugeot and is usually caused by the coil being sited in moist air.

Replacing Seat Covers

If you fancy having a go at replacing the seat covers in your Thema, here's some instructions I wrote a while back. I’m not sure if it’s the same for Dedras, but it should be similar. I'd also recommend Halfords Heavy duty carpet cleaner for cleaning the seat covers.

It’s fairly straight forward, but there are some catches that require dexterity and strong fingers. If you have any problems I can be reached on 01292 886634 after 6pm.

I'd suggest that you start with the seat squab first as it's a bit easier than the back rest.

1) Obviously the seat will need to be removed from the car first by undoing the 4 allen keys. It always helps to tap the key in with a hammer as the holes get bunged with fluff etc and applying too much force might strip the heads if the key isn't well bedded.

2) With the seat removed you should first unclip the black plastic strip from the metal cross bar at the front of the seat. This will require strong fingers. A similar clip is at the back of the seat but it's a more complicated affair with two clips that overlap onto a metal cross bar. Take note of how it fits first!!!

3) Next disconnect the black rubber bands that criss-cross under the seat cushion. These rubber bands hold the alcantara fabric taut against the cushion.

4) The only thing now holding the seat cushion in place will be two thin metal rods that run though the sides of the seat cover. To access these you will need to remove the plastic trim along the sides of the seat. With these trim out the way you should be able to prize the metal rods away from the clips that retain them in place.

5) Re-assembly is just the reverse, but you'll find that refitting the metal rods at the sides is a pain.

The seat back is a bit more difficult as the covers never seem to fit quite so snug and you may need to "stuff" slack areas of the cover with cotton wool buds. The seat back can however be done without removing the seat from the car.

1) First undo two screws at the base of the seat back so that the back pocket section can be pulled down and popped out.

2) This will reveal some metal rings that hold a metal rod through the bottom section of the seat cover to the frame. These clips need to be prised open with something like a pair of pliers or a screw driver.

3) The seat back is then held in place by a very stubborn clip at the top of the seat pocket insert and the same arrangement of elastic band tensioners as found on the seat squab.

4) There are also two plastic clips that run vertically down each side of the seat. These pop off the metal frame in the same way as the one at the top, but take careful note of how they clip onto the metal.

5) Remove the knob for adjusting the lumbar support. This is held in place by a split pin that needs to be carefully tapped out with a small diameter screwdriver or anything else that will fit into the hole in the knob.

6) Remove the Arm rest. This is done by popping off the plastic cap on the armrest. It has 4 lugs on it that can be released with a screwdriver. The armrest is then held on by a bolt (I think 16mm). Watch out there's a big spring in there so make sure you don't lose the washer as it releases.

7) Remove the plastic rings at the base of the headrest, they are a bit fragile so do this gently. They have 4 lugs like the cap on the armrest and you may need to get a second pair of hands to attack with a screwdriver from both sides. The headrest comes out easy enough if you rotate the legs.

8) The cover can now be removed, but be aware that there is a velcro strip attaching the cover about 2/3 of the way up the back rest.

9) If you are swapping a passenger seat cover onto a driver seat then you'll need to cut holes for the armrest and the lumbar adjuster. To get these in the right position you just turn the old cover inside out and use it as a template against the new.

10) Re-assembly is just the reverse, but take care to get the velcro lined up right and don't be surprised if you have baggy areas that need a bit of packing with cotton wool. If you do use the wool buds be sure to tease them out as you'll otherwise wind up with a lumpy looking surface.