1989 Caterham Super Sprint Refresh

[Origin7]

After loving Caterhams since I was a kid, I recently purchased a '89 1700 Super Sprint with 15K. It's a single-owner car that's been undriven for 4 years and needs some sorting out. I have 1 month to use the previous owner's lift and get things in order before I relocate her. 

 

All the fuel had evaporated, and the system was dry. I got some fuel into the car and primed the fuel pump. The car ran great. There are a couple of things that I see that need to be addressed:

 

1. The clutch slave cylinder is leaking badly. 

2. The upper and lower radiator hoses are cracked and leaking.

 

Are there any other things that I should do right away or check while I still have use of the lift? 

   

Edited November 17, 2025 by Origin7

[MV8]

How far are we going? Make sure the cooling fan can be switched on. I see the fan switch is not connected. Make sure the alternator is charging the battery and the temp is being displayed on the temp gauge. Replace any hard, stiff fuel or coolant hoses. Disconnect the fuel line at the carbs to let the electric pump fill a clean pail to see how clean the fuel is. Change the fuel filter and vee belt. DO not move the oil lines around unless you want to go ahead and replace them. Hot oil pushes the durability limits of rubber hose. There should be a seal kit available for the slave. Might check the diff and trans oil levels to top off. Date codes on the tires to see how old and if your test drive created some cracks. Looks well cared for but sitting is always bad.....

[Origin7]

It's only an hour to get the car home, but I'd like to take advantage of the heated shop and lift to get things done. 

 

Great suggestions! Thank you!

 

Good catch on the fan. The previous owner wired the fan to a switch on the dashboard to control it manually. I assume because it ran on the cooler side, but I am not sure. 

 

Any idea how I could ID the slave cylinder and find a rebuilt kit?

 

[MV8]

I just realized what this is. The car originally had a cable clutch but someone adapted it to hydraulic using a universal slave. I don't know about the source for the one you have, but a new slave is about $50 from speedway motors. The problem is the speedway part may have a different bore size, different line fitting, may be longer or shorter, etc so some adapting may be required. An alternative is to return to the leak-free standard cable clutch but it may require pedal modification or other small parts to make it work and you don't want to be waiting on the domestic mail in somebody else's garage. I suggest stopping several times on your way home to top off the clutch master. It may not be as bad a leak as you think.

 

The dust boot and the mounting stud is removed to fit a bolt and bracket.

https://www.speedwaymotors.com/Speedway-Pull-Type-Clutch-Release-Slave-Cylinder,7169.html?utm_medium=CSEGoogle&utm_source=CSE&utm_campaign=CSEGOOGLE&gad_source=5&gad_campaignid=23022589191&gclid=EAIaIQobChMI8Nex2qf6kAMVqjUIBR1fRBXuEAQYAiABEgIxC_D_BwE

[NSXguy]

I like to do a full baseline whenever i acquire a new analog/classic car, especially if i don't have a full history or high confidence on the state of the car. It's a great hedge against getting stranded on the side of the road. So i'll share a few things i would recommend; I personally go deeper than this but this is probably a good rational place to start and you can add/subtract as you see fit. 

 

Fuel system.

-Replace any existing rubber fuel lines (i believe they'll be 5/16" or ~8mm)

-replace fuel filter- NAPA PN 3002

-Check operation of pump if electronic, confirm fuel pressure. Webers like <3psi

-go through Webers and clean/recondition. -i would diassemble but if not comfortable; check internal filter. floats, jets at a minimum. clean any gunk at bottom of bowl. 

 

Brakes:

-Replace lines if needed. 

-Refill with new Dot 3/4 and bleed. 

-inspect front caliper for proper operation. pad likely good as they go a long way on a 7. 

-Is rear Dedion or Live axle(looks to be newer chassis based on X brace in nose so could be DD). Either way. same as front. if live axle, check brake shoes, adjust hand brake.  if dedion, check calipers/pads/handbrake

-Older 7s had a hydraulically actuated brake pressure switch. confirm operation and replace if necessary. don't forget to bleed this location as well if it has a nipple as it may affect rear circuit. 

 

Hydraulic clutch:

-Check and replace line if needed. 

-refill with Dot 3/4. 

-CLICK following Link to slave cylinder replacement -    HYPERLINK TO REPLACEMENT SLAVE CYLINDER

-Adjust clutch pedal if necessary to suit.

 

Coolant circuit: 

-Drain fluid. flush engine and radiator and replace with new green Ford motorcraft or equivalent coolant- 50/50 mix. 

-replace coolant lines- to heater and rad (can order from UK or piece together from hoses at NAPA)

-check and replace thermostat and cap.

-Inspect waterpump (relatively inexpensive), so i would just replace if been sitting in coolant for a while.  HYPERLINK TO REPLACEMENT PUMP

-Check- operation of fan switch. doesn't seem to be connected in photos. Can have on a switch if desired. 

 

Ignition:

-check distributor cap/rotor and leads. This is one of those items that would leave you stranded. I would recommend replace for -peace of mind. 

-Replace spark plugs - Champion plugs work well. (N6YC) or Autolite AR51. 

-Confirm timing with timing light. 

-Firing order FYI- 1-2-4-3

 

Oil:

-drain and replace - Use Valvoline VR1 20/50

-Napa oil filter - PN/ 1516 

 

Assess Engine Health:

-If you have boroscope; doesn't hurt to put one down the bores to gauge. 

-Do a compression check.

-Do a leak down check. 

-Check and adjust valve clearances. 

 

Drivetrain:

-Depending on gearbox, may not be able to access drain plug. If so can suck out from the top. Refill with new Redline 75w85 GL-4 fluid or equivalent. 

-Drain and replace rear diff fluid (will depend if LA or Dedion). Either way should be able to use 75w90 GL-5 Redline or equivalent

 

Suspension:

-Check all bushings for wear and replace as necessary. Can order any new ones from Chris at Redline Components (UK)

 

Electrical:

-Go through relays, fuses. ensure everything works as intended. I decided to add standalone circuits for high load components to help with reliability. 

 

Hope this helps,

Dez.

 

 

 

Edited November 18, 2025 by NSXguy

[Origin7]

1 hour ago, MV8 said:

I just realized what this is. The car originally had a cable clutch but someone adapted it to hydraulic using a universal slave. I don't know about the source for the one you have, but a new slave is about $50 from speedway motors. The problem is the speedway part may have a different bore size, different line fitting, may be longer or shorter, etc so some adapting may be required. An alternative is to return to the leak-free standard cable clutch but it may require pedal modification or other small parts to make it work and you don't want to be waiting on the domestic mail in somebody else's garage. I suggest stopping several times on your way home to top off the clutch master. It may not be as bad a leak as you think.

 

The dust boot and the mounting stud is removed to fit a bolt and bracket.

https://www.speedwaymotors.com/Speedway-Pull-Type-Clutch-Release-Slave-Cylinder,7169.html?utm_medium=CSEGoogle&utm_source=CSE&utm_campaign=CSEGOOGLE&gad_source=5&gad_campaignid=23022589191&gclid=EAIaIQobChMI8Nex2qf6kAMVqjUIBR1fRBXuEAQYAiABEgIxC_D_BwE

 

I thought something looked out of place with that slave cylinder. This makes sense, now. I appreciate the help! 

[Origin7]

@NSXguy This is really helpful. Thank you for taking the time to put this together. Everything makes a lot of sense.  

 

It has a Dedion rear end, which should make things a little easier. 

 

What is your UK source for coolant lines? These seem to be a little difficult to track down. 

 

PS: I am in CT as well. Just north of Hartford. 

 

 

 

 

[NSXguy]

Chris from Redline Components can sort you out. He's very knowledgeable on the early 7s and would be the best 1 stop shopping solution for all the bits you need. Granted,  I haven't ordered anything from him in many years so not sure how/if the shipment/tariff shenanigans have affected his desire to send stuff here, but email is the best way to contact him and list the items you want. 

 

Redline Components:   https://redlinecomponents.co.uk/

 

[11Budlite]

I believe that slave cylinder was used on that era Caterham delivered to the US in LHD form. My buddy has a '92 almost identical to yours and he has the same blue slave cylinder. When it started to leak he was able to get a replacement here in the US. I believe it was from Josh at Rocky Mountain Caterham. 

[IamScotticus]

WARNING: UNSOLICITED OPINION:

In CT/MA, unless you're racing,  I would consider eliminating the oil cooler.  I doubt you get any benefit from it up there and its more stuff to break.

These 7s shake everything loose.  An oil cooler thermo sandwich plate may not be getting hot enough to flow.  Modern oils can take the heat.

The manual fan switch may be because the thermo sw was overcooling.  At the least, changing those oil hoses to maintain flexibility is a good idea at this age.

The more you take off a 7, the better it gets. Except keep that alternator heat shield.  If you sell the 7, keep that shield, it's a gem.

And the radiator maker, CovRad, is no longer in business.

 

Looks like Long cockpit DeDion.  Ford PCD? or not yet?

Edited November 18, 2025 by IamScotticus

[IamScotticus]

look:

Im just throwing stuff on the wall..

https://www.proformancepros.com/item/5274480-universal-slave-cyl-pull-style-blue

https://www.proformancepros.com/item/6899255-slave-cyl-for-clutch-1-38-stroke?keyword=PPP-1307

https://www.piratemfg.com/cnc-slave-cylinder-blue-dune-buggy-vw-baja-bug-cn300b

https://patrickmotorsports.com/products/trawil260133

[IamScotticus]

@theDreamer what do you think that steering rack is? MIni?

[NSXguy]

I had the same blue one when I first purchased my 81 cat.  Swapped it out during my baseline process as it was leaking like yours(it’s probably a very old unit). 
 

i installed the speedway unit and decided to fab a plate and purchased a bracket and threaded heim joint to support the back of it for a more robust install. The original configuration/assembly was prone to flex. (Refer to attached photos)

links to bracket and heim joint:

Hyperlink to clutch slave cylinder bracket

Hyper link to clutch slave cylinder heim joint

 

Edited November 18, 2025 by NSXguy

[wdb]

Those wheels need to go. I'd be willing to take them off your hands...

[theDreamer]

11 hours ago, IamScotticus said:

@theDreamer what do you think that steering rack is? MIni?

I have been told that is was from BMC parts bin as used on the Morris Minor and Austin Mini. Furthermore it was modified from stock with most believing the mod had to do with changing the length of the treaded rods. There may have been other mods performed. No one has submitted documentation for this part or diagrams of actual units. I do know that these units are no longer available.

[Origin7]

3 hours ago, wdb said:

Those wheels need to go. I'd be willing to take them off your hands...

 

I am quite fond of the wheels. I'll sell you the tires though. They are only 35 years old. 

[Origin7]

@NSXguy  That's it! I like what you did with the support/mount. I can see a lot of slop which your setup would eliminate. 

[Origin7]

I know I might get roasted for this, but I’m thinking about having a local shop go through the car if I can find someone I trust. I just don’t have as much time as I used to. Does anyone know a trustworthy shop in the CT, MA, or NY area?

 

It looks like this shop has seen some Cats. Has anyone had experience with them? 

 

https://www.automotiverestorations.com/

[MV8]

The slave mounting support should be attached to the engine (versus the chassis) so it can move with the bell housing as the engine rocks under load. The rocking movement is much greater when driving than what can be seen blipping the throttle out of gear.

 

The purpose of the support plate is to keep the slave body from moving away from the bell when the pedal is not being applied.

 

For someone adapting this without replacing an existing pull slave, the slave body could be mounted a 1/2 inch further forward to get it off the bell opening (rod would just pass through so no need for a flange bushing in the bell) and a stiff support bracket made using the full length stud provided but removed for this installation/repair.

 

 

[NSXguy]

That's a good obvservation. I definitely agree that ideally, an engine mounted bracing should be the goal.  While not impossible to do on a xflow (easier on other engines), practically a bit more involved on a x-flow due to availability/proximity of existing mounting locations/threaded holes/bosses for a bracket. I suspect it is for this reason that many of the Xflow 7s cylinder installations i've observed are as they are and don't come with a rear brace; which still works OK but IMO not ideal for the optimal performance. 

 

In my case, I did consider a few engine mounted alternatives when doing the "upgrade";  but not wanting to implement an exotic solution, opted for the simpler setup pictured. As a hedge, i purchased a spare cylinder in case the rigid mounting resulted in premature/accelerated failure, but so far have not needed it as the unit has worked reliably through many years of normal city driving and several days of hard driving on track. 

 

YMMV- By no means the only viable approach; one can expect with an assembly prone to more vibration, or overly compliant mounts, results might vary.  And of course, a concentric slave cylinder eliminates these concerns, but comes with its own set of trade-offs. such is the nature of the beast. 

 

I would say, as an improvement to my original install, rubber bushes can be added for and aft of the heim joint or on the mount/bracket for some damping.