Solis 20 & 26 won't start or runs poorly? Troubleshooting guide
Does your Solis 20 or Solis 26 not start, run irregularly, or overheat? In this troubleshooting guide, we go through the likely cause and solution per symptom — from the fuel system to the hydraulics and electrical system. We start with the simple, inexpensive causes.
Suitable for the entire series: Solis 20, Solis 20XL, Solis 26, Solis 26XL, and Solis 26HST.
Begin bij de eenvoudige oorzaken: brandstof, accu en filters.
Solis 20 & 26 won't start
Possible cause
Solution
Incorrect starting procedure
Follow the correct starting sequence (neutral, clutch engaged, preheating)
No or insufficient fuel
Check fuel level (min. 5 L Solis 20 / 6 L Solis 26)
Air in the fuel system
Bleed the fuel system
Clogged fuel filter
Replace filter
Faulty injector
Have injector checked/replaced
Battery/connection (see practical issues)
Check battery terminals and main switch
Solis 20 & 26 runs irregularly or lacks power
Symptom / cause
Solution
Clogged fuel filter
Replace filter
Overheating
Check cooling system (see below)
Operating temperature too low
Check/replace thermostat
Incorrect valve clearance
Adjust to 0.25 mm (intake/exhaust)
Dirty air filter
Clean or replace
Excessive load / gear too low
Reduce load or shift down
Solis 20 & 26 overheating
Cause
Solution
Faulty radiator cap
Replace
Dirty radiator fins
Clean
Insufficient coolant
Top up and check for leaks
V-belt tension too low
Adjust tension (deflection max. 10 mm)
Faulty thermostat
Replace (Solis 20: 76.5 °C / Solis 26: type 1)
Clogged cooling system
Flush and clean
Solis 20 & 26 hydraulics not working or too slow
Cause
Solution
Response valve closed too far
Turn back the valve
Oil level too low
Top up
Hydraulic strainer clogged
Clean or replace
Faulty hydraulic pump
Have it checked
Solis 20 & 26 electrical: not charging or not starting
Check battery voltage; clean connections; check starter motor
Solis 20 & 26 brakes not working properly
Symptom / cause
Solution
Brake performs poorly
Adjust brake pedal free play (25-30 mm)
Tractor pulls to one side when braking
Adjust both brakes equally
Noise when braking
Check and adjust brakes
Solis 20 & 26 oil pressure light is on
Cause
Solution
Oil level too low
Top up to the correct level
Wrong or poor-quality oil
Use the correct, clean oil
Faulty oil pump
Have it checked/repaired
Is the oil pressure light on while running? Turn off the engine immediately to prevent damage, and check the oil level first.
Known practical issues with the Solis 20 & 26
In addition to the standard troubleshooting table, owner experiences reveal a number of recurring issues. Good to know, each with the likely cause and what to do about it:
Poor cold starting due to the main switch. A common cause of difficult starting in cold weather isn't the engine, but the battery isolator/main switch, which loses conductivity at low temperatures and passes too little current. Check and clean the switch and battery terminals; replace the switch if in doubt.
Won't start due to a safety switch. The tractor has safety switches (clutch, brake pedal, PTO). A faulty or misadjusted switch — for example, on the brake pedal — can prevent the starter motor from turning. Check the switches and wiring before suspecting the starter motor.
Difficult or stiff shifting. Complaints about difficulty getting into gear or hesitation in the H-M-L range often trace back to a poorly mounted or adjusted range lever and clutch adjustment. Check the clutch pedal free play (25-30 mm), the lever linkage, and use the correct transmission oil.
Hydraulic and oil leaks. Leaks at hydraulic lines and couplings are reported, sometimes early on. Periodically check hose couplings, the response valve, and seals, and retighten connections.
Power steering leaks (Solis 26). On the Solis 26 with power steering, oil leaks at the steering cylinder and lines are reported. Check the lines and seals and use the correct type of oil.
Front axle, toe-in, and 4WD. Pay attention to the front axle: change the differential oil according to schedule, check hub play, and keep toe-in at 3-6 mm. Grease the steering knuckles/tie rods and bushings periodically to prevent seized hubs and 4WD problems.
Battery not charging / alternator wiring. In addition to loose or dirty battery terminals, wiring issues at the alternator are also reported. Check the connections and V-belt tension if the battery keeps draining.
Naming confusion and grey imports. There are various versions (20/20XL/26/26XL/26HST) and build years before and from 2017 with a different air filter. When ordering parts, always check your serial number and engine code (Solis 20 = MVL3E, Solis 26 = MVS3L2).
💡 Shop4trac tip: Many starting and running problems start with fuel. If in doubt, first replace the fuel filter Solis 20-26 (SKU-150019) and bleed the system. Keep the engine code in mind when ordering a starter motor or alternator — the Solis 20 (L3E) and the Solis 26 (S3L2) use different parts. Part numbers from real-world experience are for reference only; always verify against your serial number.
