Richard in the UK writes:

"Hi Enrico,

I recently suffered a failure of the high pressure feed to the clutch slave cylinder on my Merak SS. The LHM tank was fully drained and the clutch/brakes failed due to fluid loss. Before this failure the clutch slave cylinder and the clutch plate had done less than 200 miles.

I have now replaced the failed high pressure copper pipe, bled out the brakes and then bled the clutch (using Andy's method he describes so well in an earlier answer on your site). A lot of air came out of the o/s front brake, very little from the other brakes and quite a bit from the clutch slave cylinder.

My problem is now that the clutch doesn't feel as good as it did before the failure. The initial movement of the pedal is very light although the clutch slave cylinder stills works and engages/disengages the clutch. I suspect that there is still air in the low pressure circuit to the clutch slave cylinder but I don't know where to look for it!!!

Any help would be appreciated.

Richard."

Reply from Andy:

Re: Merak - Brakes!

"This can be tricky to sort. From what you say, it is likely that you are still getting air in the system. In theory, even if you have lots of air in the brakes, you should still be able to get a decent clutch pedal. I presume you have tried the "bleeding process" more than once. If so, you could have a clutch master cylinder fault or a leak on the headlight circuit.

Andy."

Harry in Canada writes:

"Hi Enrico,

Talked to you last summer about my 1979 Merak SS and its oil burning problem. Well it is winter here in Canada and you need a project when it is 35 below C. I have removed the engine and will remove the heads today. I want to check the bore diameter and piston clearance.

What are the correct maximum and minimum diameter of the bore and piston size in thousands. I have run a leak down test and these are the results.

Number one cyl. at TDC 50% No.2 30% - No.3 25% - No.4 15% - No.5 18% and No. 6 20%.

There is little to no leakage through the valves. I feel there could be the wrong ring size installed or damaged liners. I also tested leakage with piston at 1.5 inch past TDC. the readings were 70% - 60% - 62% - 25% - 58% and 24%.

Also this engine has a gear style chain tensioner which is operated by oil pressure. Did they use the Renolds chain in 1979 and how do you determine if this tensioner is at it's max adjustment?

Last question. Would a 79 SS US spec Merak use a ZF transmission?

Thanks for the great site.

Harry."

Reply from Andy:

Re: Merak - Smoking!

"The standard bore size for an SS is 91.6mm. This should be stamped on the piston crown. There are oversizes available up to 92 mm I think. You should be looking for no more bore clearance than 4 thousandths and of course no ovality. Usually, the liners show signs of damage where piston rings have partially seized or where there has been water corrosion. This plus the high possibility that your problems could be caused by a broken piston ring or rings will dictate the way forward!

Sounds like you have the late type tensioner which is self adjusting and very reliable. You just need to check for wear in the chain rather than adjustment. If in doubt, new chains are available and not expensive. You would be wise to renew the two secondary chains to the cams if there is any wear at all in them - these you can check by looking for wear on the split links.

Apart from a couple of special order cars, all Meraks used the Citroen SM type transaxle and not ZF. Good luck and keep warm!

Andy."

John in the UK writes:

"Hi Enrico,

I am in the process of rebuilding a pair of spare front hub and disc assemblies that I have. The front wheel bearings are plain sealed ball races, not taper bearings, is this correct? Also the inner bearing is retained with a locking ring. This ring has proved to be almost impossible to remove on one side, and definitely impossible on the other side. I made a tool to remove this ring with handles 3 feet long! but to no avail. In the end I had to machine them out! Is this normal. Could you also advise me on the correct way to remove the wheel retaining studs. I have had them under a hydraulic press with no result, so I suppose that I'm missing something somewhere. Finally, in a previous reply Andy stated that in order to prevent the entry of fumes into the interior of the car the tunnel had to be sealed, Is there supposed to be a rubber gear lever gaiter in place?

My car only has the leather gaiter which is attached to the tunnel cover.

Many thanks.

All the best,

John."

Reply from Andy:

Re: Merak conversion.

"The sealed plain ball races are correct. The locking ring is always difficult. Should have a small grub screw fitted in it to open up and lock the thread which in theory can be undone. However, after a few years, this is all rusted solid anyway. Wheel retaining studs I THINK are screwed in to the hubs with the ends peened over. Certainly like that on other models but can't remember trying to extricate one on a Merak. Should be rubber gaiter on metal part of transmission tunnel I think under cover panel and under leather outer gaiter.

Andy."

Richard in the UK writes:

"Hi Enrico,

Can you suggest a method for removing the n/s rear brake disc with the engine in situ? I need to repair a stripped driveshaft bolt thread.

Thanks,

Richard."

Reply from Andy:

Re: Merak conversion.

"This is easily achieved with the engine and transaxle in place. You will need to remove the foot brake and hand brake calipers on that disc (which in turn probably is easiest to do with the auxiliary subframe removed). You will have to remove the exhaust manifold on that side also and of course the drive shaft. The disc is retained to the output shaft on the transaxle on studs with nuts. These are a little tricky but far from impossible. As with everything Merak, it seems that you have to do quite a lot of dismantling to get to the piece you need!

Andy."

Carey in the USA writes:

"Enrico,

My Merak has a small hose attached to a "t" on the main brake booster line under the front hood - all the small vac lines are off the switch and I need a routing diagram to set it all in order.

Does a diagram of the various air controls exist, or is it going to be trial and error? I think there are 4 outlets on the switch and 3 vac motors- can you point me in the right direction?

Thanks for hearing my problem!

Carey."

Steven in the USA writes:

"Enrico,

Do you have any information on the red US spec Merak where the front bumper has been removed and replaced with grillwork? I would like to get an idea of how it was done and what the owner did in the rear of the car.

Thanks,

Steven ."

Reply from Andy:

Re: Merak conversion.

"We have no experience of doing this on a Merak but we have converted a couple of Boras over the years. It depends on how serious you are about making the car look original to Euro Spec as at the front, the peak in the centre of the grille aperture would need to be made (missing on US spec). This is a bodyshop job. Then you would have to cut out the US bumper supports and make some thin vertical struts which the Euro spec bumper sections fix to. This would be quite easy for a skilled bodyshop but would undoubtedly involve painting the nose of the car afterwards.

At the rear, the biggest problem is that the bumper on US cars is at a different height to the Euro spec and again, although it is possible to raise the bumper up to fit under the rear light units, making and fitting the bumper iron tubes is a skilled fabrication job. Then there is the problem of the exhaust, as the euro car tailpipes exit where the US bumper was. On the Boras that we did, we made up a grille to cover that aperture and a one-off exhaust system so that the tailpipes exit in the European way (!).We could not change the exhaust to totally Euro spec as the rear gearbox mounting was different (Not sure about Merak) which did not allow the transverse silencer to sit in the right place. We had to repair the bulging US rear valance as a consequence. The finished result looked pretty good but not totally original.

So it is possible to convert a US spec car to Euro bumpers and make it look almost as per original - but not quite. One of the biggest problems however, is finding a set of euro bumpers as they are second hand only, scarce and therefore expensive.

Hope this helps,

Andy."

Richard in the UK writes:

"Hi!

Can you tell me which parts need to be removed in order to take both fuel tanks out of the car?

The engine, gearbox and suspension are already removed.

Thanks,

Richard."

Reply from Andy:

Re: Merak fuel tanks.

"You have to remove the rear seats from the car, cushion just pulls out, back rest has one screw to base on tab and then unhooks. This gives access to a panel on either side which is bolted/screwed into place. You will have to carefully peel back the centre back cover, the trim piece around the rear window and the rear side panels to get access to all the fixings. After that the panels will come out and you have access to the tanks. It may also help to remove the two plastic tank covers in the engine bay. Disconnect fuel hoses from base of tanks and watch out for breather hoses, sender wiring on top. Remove the fuel filler flap and its neck piece. The tanks are not bolted in, just wedged in place with what looks like loft insulation. Pull this out and then the tanks will fiddle out. Not a difficult procedure but a bit long winded.

Cheers,

Andy."

Charles in Australia writes:

"Hi Enrico,

Thanks for the advice regarding vacuum advance on Merak timing with electronic ignition.

I need your help on the hydraulic pump operation now. A year ago when I did a complete body restoration of the car, I replaced both rubber couplings on the intermediate accessories shaft. Last month while I was driving, one of the couplings (the one at the engine site) was completely torn apart. Straight away I lost all my hydraulic pressure. The clutch became heavy and the lights dropped down and could not rise back.

****Is it normal to loose the pressure immediately when the pump is not rotating? What happened in the pressure in the accumulator?*****

I drove the car slowly home. I thought maybe the pump seized and that caused the coupling to break apart. I took the pump to a local Citroën mechanic and he said that since it rotates freely it is nothing wrong with it. I also noticed that the pump was out of alignment with the engine. It needed to move 5 mm up and 5 mm right. This definitely caused strain on the couplings. I placed the pump back on the car after refilling it with hydraulic oil. Before connecting it to the shaft, I tried to rotate it by hand. It rotates with some resistance from the pistons. The more turns I rotate the pump the more the resistance increases. I assume it is building up pressure. The pump resistance is much higher than the resistance from the alternator.

***Is normal to get this kind of resistance from the pump?****

I am worried not to damage the couplings again because of a faulty pump. In the parts book, there are spacers at the pump and the engine site of the couplings. My car does not have these spacers. Are they needed?

Another issue now. The horn relay which I suspect is faulty, is located in the duct underneath (and slightly behind) the gear stick, I hear a clicking noise when I press the horn button.

*** Do you know how I can get access to this area?***

Thanks in advance.

Waiting for your comments,

Charles."

Reply from Andy:

Re: Merak exhaust manifolds.

"Hi,

1. No, you should certainly not lose all pressure immediately. In theory, there should be enough accumulated pressure in the system to allow a stop from maximum speed which clearly is not the case here. Dangerous and glad you drove home slowly.

1. The alignment problem is certainly something that needs to be attended to. If need be, you should try to adjust the whole cross member on which the pump sits. The couplings are usually very reliable and so there must be a reason for this early failure. The couplings have metal washers that hold them together. Are the washers present on yours? The spacer issue is only really relevant as a means of adjustment. When the couplings are fitted, are they under fore and aft stress because they should be straight?

The way you describe the pump sounds normal and it would be very, very unusual for a pump to seize. However, before you try it all again, consider that you must find out why you have no accumulated pressure. If you have no record of the spheres being recharged then get them done. It's not expensive. That would be the main sphere next to the pump and fixed to the regulator and also the two brake spheres in the front luggage compartment behind the bulkhead panel. Consider also that if the car has been used like this for some time, the pump will have been working overtime. If you have no record of the pump being overhauled then do this at the same time. I can only recommend Pleiades for this work.

However, you may find that having done all the above, you are still lacking accumulated pressure. One way to check is to run the engine until the low pressure warning light goes out, switch off and work the headlamp pods up and down. If you have just overhauled the accumulators then you should get them to rise and fall about a dozen times before they run out of pressure. 6 is the bare minimum. Presuming your car is an SS, the other check is to run the engine at idle and listen for the pump and regulator - best done with an ear in the engine bay. You should hear a whirr - click as the pump charges and then the regulator cuts in. This should occur every 30/45 seconds. If it is more frequent than that, take the lid off the hydraulic reservoir. Look for fluid dribbling back into the tank through the pipe that is connected into the neck (the return from the clutch slave cylinder). If this only occurs during operation of the clutch then all is well, but if there is a constant dribble, you need to get your clutch slave cylinder overhauled as it is bleeding pressure away from the pump all the time. Again, Pleiades.This is not an exhaustive list of all possibilities for LHM system problems so come back to me if you are still in doubt.

3. Take the seats out, take the transmission tunnel cover out (self tappers) and then you will see that there are two inspection hatches in the tunnel (one around the gear lever).

Cheers,

Andy."

John in the UK writes:

"Hello again Enrico,

Another question for Andy (one day he's going to get fed up with all this!)

What are the upper and lower limits (minimum service thickness) of the front and rear brake discs?

I have a spare set and I would like to re-grind them to make them serviceable.

All the best

John."

Reply from Andy:

Re: Merak exhaust manifolds.

"Hi,

There is no real info available on this. The Merak drivers handbook states that the max thickness of discs is 20.5mm for front and 12mm for rear. We have successfully ground fronts and rears but I cannot say a minimum. Certainly with the rears, you can get away with a reasonable amount as they don't do a lot of work. Fronts are a different matter. LHM systems are hard on brakes anyway and so grinding front discs should be kept to an absolute minimum. If you have a spare set of rears then you are a lucky man as these are not currently available - look after them!!!

There are two other aspects of Merak brake discs that can be a problem. On the front, the actual disc is held on to its bell by a retaining ring which is bolted through by a number of small set screws. This can all rust horribly and you can have a rattling (or even detached) front disc as a result. Check this and sort if you have to!!!! This also means that if you do have front discs ground, then you must mount them on the bell that you are intending to use on the car when they are ground as there is no guarantee that they will be straight otherwise. Check for run out.

On the rears, the brake discs are bolted onto the transmission output flanges and then the drive shafts are bolted to the disc. Therefore, the centre of the disc transmits drive and breakages are common. Check thoroughly for cracks around the bolt holes and drive peg holes because your discs may be scrap just because of this.

Cheers,

Andy."

David in ? writes:

"Hi,

Any chance on some advice for getting the headers off a Merak. Disconnected one side of the suspension A-arms, but it is appearing the engine will need to be hoisted up. Any ideas.

Regards,

David."

Reply from Andy:

Re: Merak exhaust manifolds.

"Hi,

Ideally, not only do you need to remove the lower wishbones from the chassis end, but also the fuel link pipes and their heatshields (which involves draining the tanks). It is then possible to fiddle the manifolds out (assuming the rest of the system, the rear valance and grille are already out). It should not be necessary to move the engine.

Cheers,

Andy."

Charles in Australia writes:

"Hi Enrico,

I have a 1981 Merak SS with European specs. Does anyone know what are the correct tune up (ignition) settings?

I bought the user manuals from MIE, but still notclear.

There is a graph which shows 0 degrees BTDC at 1000prm and increases to 15 degrees BTDC at 4000prm and stays at 15 at higher than 4000 rpm. That means that the maximum advance will never exceed15 degrees BTDC.

Also I have read in your discussions that the vacuum advance should not be connected on the electronic distributor (all the advance should be mechanical which is done by the bob weights in the distributor). Is it normal not to have any vacuum advance?

I also need to replace the relay for the air horn. Anyone knows from where I can access it?

Your advice will be much appreciated.

Charles."

Reply from Andy:

Re: Merak ignition timing.

"Hi,

On a car with points (Ducellier ignition) it is possible to do a static setting and this should be at 6 degrees BTDC.

On a later car with Hall sensor (Bosch ignition) you can't do this but should set on a strobe using the marks visible through the bell housing hole under the distributor to around 8 degrees BTDC. Some cars will take a little more than this depending on the state of your petrol.

As your car is a 1981, it is most likely to be the Bosch version.

The book is singularly unhelpful on this subject and anyway, only deals with early version. Absolutely definitely the vac advance should not be connected and the mechanical advance will do all you need.

Hope this helps,

Andy."