CLK W208 convertible top not working? Check convertible top pump A2088001748

A convertible whose top won't open is annoying – one whose top won't close is a real problem. On the Mercedes CLK convertible of the A208 / W208 model series, an electrohydraulic unit handles the entire top movement: a pump motor generates the hydraulic pressure, and a valve block distributes it to the cylinders. If this unit fails, the top doesn't move at all or only partially. Before you order a pump, though, a systematic elimination is worthwhile – the cause is often one step earlier. This guide shows how to proceed.

Symptoms

Typical fault patterns of the convertible top operation and their likely causes:

Symptom	Likely cause
Top can be neither opened nor closed, pump stays silent when the switch is pressed	No voltage at the pump motor (fuse, relay, cable) or pump motor defective
Pump is audibly running, but the top doesn't move	Valve block of the convertible top pump doesn't switch, or alternatively too little hydraulic oil
The top only moves partially or stops in an intermediate position	Pressure loss due to leakage or declining pump output
Traces of oil in the trunk, at the top compartment or at the cylinders	Leaking hydraulic line, fitting or cylinder – not necessarily the pump
Not to be confused with: Besides the top, other electrical consumers fail	More likely a fault in the power distribution – see Checking the relay unit and in general Checking the working relay

Causes

The hydraulics of the CLK convertible are now over two decades old. The pump motor works rarely, but then under high load – carbon brushes and commutator wear, and bearing points become stiff. Another point is the hydraulic fluid itself: it ages, absorbs moisture and slowly loses volume through leaks. If the oil level drops, the pump draws in air, the pressure collapses and the top stops moving.

The valve block is the second weak point. Its solenoid valves control which cylinder gets pressure and when. Deposits in the oil, corroded plug connections or burnt-out coils mean that the pump runs but the pressure doesn't arrive where it is needed. Because pump motor and valve block form one unit on the A2088001748, the complete unit is usually replaced when it fails.

Testing it yourself

Start with the inexpensive checks before you replace parts on suspicion:

1. Check fuse and relay. Check the relevant fuse and the relay for the convertible top operation. How to narrow down a relay by swap test and measurement is described in our guide Checking the working relay.
2. Listen to the pump. Have a second person operate the top switch while you listen in the trunk. Silence points to a power supply or motor problem; a running motor without top movement points more toward the valve block or low oil.
3. Check hydraulic oil and leaks. Check the oil level at the unit as well as lines, fittings and cylinders for traces of oil. A leak must be fixed before a pump replacement, otherwise the new pump will quickly end up in the same condition.
4. Measure the voltage at the pump motor. Use a multimeter to measure whether voltage reaches the pump motor connector when the switch is pressed. If voltage is present and the motor still doesn't run, the pump motor is the culprit.
5. Read off the part number. If the suspicion about the pump is confirmed, read the number off the removed unit and compare it exactly with A 208 800 17 48.

Solution

Once the convertible top pump has been identified as the cause, replacing the complete unit of pump motor and valve block is the remedy. We carry the genuine Mercedes convertible top pump with the part number A2088001748 (subgroup A 208 800 02 30) for 349,00 €. Please note: it is a removed used part whose function has not been tested. It is sold in its present, inspected condition; see the product images for the exact condition. Shipping within Germany is free, and a 60-day return policy applies.

The part is a one-off. If it has already been sold, take a look at all spare parts or make a quick call – we'll check whether we can source the matching number.

Compatible vehicles

Model series	Model	Model year
A208 / W208	Mercedes CLK convertible	1998 – 2003

Details according to product data. The exact part number is decisive – please compare it with your old part before buying, or send us your VIN (chassis number) and model year.

FAQ

How can I tell whether the convertible top pump or the valve block is defective?

If the pump motor doesn't start at all when the top switch is pressed, the cause lies in the power supply or the pump motor. If the pump is audibly running but the top doesn't move, that points to the valve block. On the A2088001748, both are in one unit.

What is the part number of the convertible top pump on the CLK convertible A208?

The pump in our offer carries the part number A 208 800 17 48 (A2088001748), listed under subgroup A 208 800 02 30. Compare the number 1:1 with your old part before buying.

Does convertible top pump A2088001748 fit every CLK convertible?

According to the product data, it is intended for the CLK convertible A208 / W208 of model years 1998 to 2003. We make no statement for other model series or model years – if in doubt, send us your VIN (chassis number) and model year.

Where is the convertible top pump installed on the CLK W208?

The hydraulic unit is located in the trunk area or the top compartment, respectively. From there the hydraulic lines run to the top cylinders.

Has the offered convertible top pump been tested?

No. It is a removed genuine used part whose function has not been tested. It is sold in its present, inspected condition; the product images show the exact condition. Shipping within Germany is free, and a 60-day return policy applies.

KFZTeile-Thot is a specialist business for tested and refurbished Mercedes parts with its own test benches and has over 1,000 positive eBay reviews. Not sure whether the convertible top pump fits your CLK convertible? Call us at +49 179 8991069 (Mon–Fri 8 am–6 pm) or use our contact form – we'll check the fit against your chassis number free of charge.