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HSHC Fluid
what hydraulic oil for the pump
Yes you should put fluid back in before you lower the roof, otherwise you could damage the new pump. And yes you should put the reservoir plug in before trying it or you run the risk of leaking fluid out and damaging the new pump.
Have you tried topping up the hydraulic fluid tank for the electric roof, which is located in the boot on the left hand side under the felt? Fluid for this can be bought from Halfords for about £15 a litre.
If the motor is working check the hydraulic fluid level in the boot which is attached to the motor - if this reservoir is not at least half full there wont be enough power to move the hood into place. If there is fluid in the reservoir, run the motor and if this fluid level does not temporarily decrease, the pump ain't pumpin the fluid! Usually this is due to broken impeller blades in the pump - cheaper fix from dealer than a new pump thankfully. However, its probably the fluid levels. Check for leaks around the casing of the reservoir. New casings are cheap on eBay and easy to fit.
Most American convertibles use a hydraulic pump in the trunk to raise and lower the roof. The problem can be as simple as a blown fuse or as difficult as having to remove and disassemble the pump because there is gunk stopping it from turning.
The Wembley stadium has a movable roof and this depends on a hydraulic system to move the huge cover. The retractable roof allows the sunlight cover to be monitored and that allows the grass to grow.
Go in trunk; remove 4 screws from the pump cover (2 at either bottom corner, 2 at top close together) and remove that. There is a gold coloured nut sitting atop the now visible reservoir. Unscrew that. You can now top up the reservoir VERY slowly (use a small funnel otherwise the hydraulic oil will get everywhere) and reverse process when done. Only 5 minute job. THIS IS FOR A MK3 (93-98) I think its same for other models too, certainly MK4's.
Close hydraulic valve on pump( In boot pasenger side just in front of rear lights),pull on tape hanging down in ski box(cubbyhole in boot)and operate lock on lid.
take out the spare tire from the trunk. you'll see a black raised cover...there are 3 10mm nuts holding it down...they are easy to take off remove the black cover. you'll be looking at the hydraulic pump and resorvoir. I don't know why you need to access this pump. On the center console, the covertible top switch...that big red one...does it flash or stay lit? Has the pump stopped responding? There's an automatic shut off that protects the pump from burning out. Are you leaking fluid from the system? If you have oil seeping down from around the visors, you will need to replace both of the servor units. There is also another hydraulic system for the rear part of the top's system, which is behind the boot section. Also...the system's computer will need to be reset (clear the codes) at a dealer after you replace whatever is needed. You can also access the top manually....there's a roof tool that you should have...check your owner's manual on how to perform this. BTW....the dealer charges nearly $300.00 for each of those hydraulic servos....there is a guy in Missouri that rebuilds them for around $100.00 for 2.
Sounds like the Hydraulic pump seal has failed. Dealer says that this common as the vehicle gets older. I believe the kit is around $75 from the dealer.
If memory serves me correctly, it is either the hydraulic pump for the soft top, or the soft top latch itself. Both contain hydraulic fluid and will cause the leak from your visor area on a '92 SL.I drive a 98 SL 500, had a leak in the same spot. Dealer wanted to replace the whole hydrolic system for the roof. I put Stop Leak in the system, and 5 years later, it is still working great with NO leaks. New hydrolics, $3000.....stop leak $5...u decide