'88 SLS conversion questions

Hey all, I plan on taking on my SLS conversion in the next couple days. I have a few questions before I start taking apart the rear. I bought the conversion kit from a Florida Jaguar dealership, but there was no bleed screw included in the kit, which my Haynes manual tells me would be included. The parts guy from Florida tells me there’s a bleed screw in the existing SLS parts, but he doesn’t know exactly where. Anybody know where I would find this screw? Any general advice and tips would be appreciated!

bleed screw for what? Are you removing the sls?

Yes, I’m converting from SLS. I need the bleed screw to plug up the valve block in the front of the car, where the hydrolic line would be taken out.

mine just has a plug in it where the line was disconnected

That’s the bleed screw… I’m trying to figure out where that came from. And any other advice from people with experience doing this conversion.

I stand corrected.

sorry the photo was off but mine does have a bleed screw, looks like a Schrader valve

3rd time is a charm more like a grease fitting

That’s the one. It’s been difficult to find any instruction on this process. One half assed video on YouTube, and I’ve yet to find someone fully document the process via browsing forums and the web in general.

If its a bleed screw would one from a brake caliper work?

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Does this post from the archives help?


The bleed screw is removed from the rear damper and used in the valve block. (as in Bryan’s post)

I can’t even remember how many of these I did over the years!!!(My record is 45 minutes after the 3rd one in a day)


45 minutes :skull_and_crossbones: I could have used you last night. Started at 9pm, finished around 5am this morning. Ran into a few complications, to say the least. But it’s running alot smoother. Night and day difference. My only remaining question is do I top off the mineral oil? If I researched correctly, the same system that used to govern my rear suspension, also assist my braking in this model, right? Any tips on post conversion maintenance?

You need to find and read Jaguar Publication S_73 POWER HYDRAULIC SYSTEM.

The .pdf is over 4 mb so I cannot post it here.

Gus should have it on his sight since I sent it to him a few decades ago.(jagrepair.com)

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Demetrius …

The leaky hydraulic system that uses the green castor oil powers both the rear self leveling shocks and the hydro boost brake system. Now that you’ve eliminated the SLS you still need to maintain the system for the brakes.

Many people have gone to a vacuum brake booster and this completely eliminates the entire hydraulic system and it’s many … many troublesome, leaky parts and VCM warnings. It’s a very common and inexpensive conversion.

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Thank you for the website! A ton of useful information.

Now I’m hearing a rattle in the front driver side suspension. I’m not sure exactly where yet. I want to replace the whole front suspension, but I’m not sure where or what to order for parts!

Any suggestions?

Thank you for the heads up! Time to start researching another conversion.

Probably the foam bushes for the front shocks as the easiest repair proceeding to the front and/or rear subframe bushes as worst case SNG Barrett, Moss/XK Motors or Jaguar Heritage spares will have the parts.

Demetrius …

There are vacuum brake booster conversion kits available for $600-700, which is a real rip off. All you need is a used or rebuilt XJ6 series 3 booster (plenty available for around $200 or less) and an aluminum adapter plate that you can easily make yourself for about $30.

You say you have a “rattle” up front. This usually involves something loose or the exhaust pipe touching the frame. A “clunking” noise is usually, as Robin pointed out, the front shock bushings.

Found a guy who collects XJs and props them up along the thruway in my area. He has one identical to mine, out of the 8. Hopefully I can find the vacuum booster in there.

Ideally I want to rebuild the entire front suspension at the same time.

Thank you to the veterans here for your direction, your in information is more prescious than these parts that are increasingly hard to find!