I have a diesel (DDIS) version of the Suzuki Ritz/Splash. I would like to re-fill the engine coolant, as it has been topped-up for a long time now, and might be mostly water than actual coolant right now. I want to find out a standard operating procedure for doing this repair, and possibly other relevant things to be taken care of.

  1. Where to find the coolant drain cap/bolt, and how to drain it.
  2. What is the coolant grade/type to be used.
  3. What is the proportion of coolant and water to be used in the system.
  4. After re-filling, what is the procedure to make sure the process was done right.

I have basic hand tools and accessories at my disposal.

enter image description here

This model doesn't have a cap on the radiator, but the cap is on the overflow reservoir. The white jar towards the right of the battery has this cap.

  • Will you recognize a good answer?
    – Solar Mike
    Commented Feb 8, 2019 at 10:06
  • @SolarMike I have awarded the bounty points to one of the answers.
    – C--
    Commented Feb 11, 2019 at 9:00

3 Answers 3


There should be a petcock valve in the lower middle of that radiator. Here's a picture; it's the white gizmo at the bottom. Take the radiator cap off before opening the petcock to allow complete draining.

Maruti radiator Radiator Filler Neck and Petcock

Zerex Asian and Mak SuperKool are a few brands that have compatible coolant that you should be able to find locally. Or you can get the genuine OEM stuff, but it is likely to be expensive. It is very important to get the proper compatible coolant for this vehicle, as diesel coolants sometimes have additives to prevent cavitation (small bubbles) and erosion of wetted parts caused by the "knocking" sharpness of high compression diesel engines.

Mak Super Kool Maruti Genuine Coolant

The proportions are probably safe at 50/50, but in a very hot climate you may be able to use more water and less coolant. The coolant bottle will direct the proportions based on your climate range.

After you refill, you'll want to run the vehicle at idle with the radiator cap OFF and the heater ON, until you no longer see any bubbles in the filler neck. If there is no radiator cap, there may be a small bleed screw on the thermostat housing. You can crack this open (only a few turns) until you no longer see bubbles or foam coming out. I'm pretty sure your radiator will have a cap and a filler neck.

After this, the coolant level has probably dropped as the air has been bled out and replaced with the coolant mixture. Turn the vehicle off, let it cool for a while, and top up at the radiator neck. Also make sure the overflow reservoir has the proper level.

Clean up your mess as there is sure to be some, and dispose of the used coolant properly - it really shouldn't be dumped on the ground.

That should do it! Good luck. As the previous poster mentioned, it's not hard to do - just take your time.

  • This particular model has no radiator cap, and the overflow reservoir acts as the coolant filling point as well. Although, if I keep the cap off and run the engine for long, wont the thermostat open at one point, and get the cooling system pressurized, leading it to splash the coolant out of the neck?
    – C--
    Commented Feb 8, 2019 at 9:57
  • I have also added a picture of the engine bay to point out the radiator cap location.
    – C--
    Commented Feb 8, 2019 at 9:59
  • 1
    That cap you show is designed to make sure the pressure in the system is increased to increase the boiling point of the fluid. The thermostat opens based on engine temperature as long as there is sufficient fluid in the system.
    – Solar Mike
    Commented Feb 8, 2019 at 10:05
  1. very good chance at the bottom left of rad, if not just pull off the bottom hose
  2. doesn't really matter but if you want by the books google it...
  3. Depends on the product you choose and operating temperature
  4. Does it overheat? if yes you did it wrong if no you didn't.

This is a very simple job, a drain pan and screwdriver is all you need

Why are you topping off the coolant so often? leak or blown head gasket eating it? T

  • The topping was because there was a leak on the top hose. I have replaced it recently, and now wants to re-fill with new coolant.
    – C--
    Commented Feb 5, 2019 at 6:43
  • Where to find the coolant drain cap/bolt, and how to drain it.

As others have stated, there should be a drain off of the bottom part of the radiator. It should look like a fitting which really doesn't do anything (twist knob on it). It may have a drain tube pointing down. If you cannot find it, disconnect the bottom radiator hose and let it drain. This lets a lot more go a lot faster, so be careful of it and ensure you contain it so as to not endanger the environment.

  • What is the coolant grade/type to be used.

Since I'm not from India, nor do I know what brands are "good" or "bad", I'll defer to @SteveRacer's answer as his advice seems sound.

  • What is the proportion of coolant and water to be used in the system.

Coolant should be used at a 50/50 mix of coolant to water (1:1 ratio). Check the bottle of whatever coolant you end up purchasing. It will give you the ratio you need which should be used in your climate. To make it easier, you should be able to find what is called pre-mix. This gives the 50/50 mix directly where you don't have to add water or worry about ratios. If you do plan to mix it yourself, ensure you use ionized water (or at least distilled water). Do not use tap water, as this will introduce contaminants which will cause sediment in your cooling system, and will reduce cooling efficiency.

  • After re-filling, what is the procedure to make sure the process was done right.

This is the easy part (and the real reason I've added another answer to your question) ... Fill it up through the reservoir you pointed out in your picture. Your system has an expansion tank and will self purge. Coolant flows through this bottle at all times and allows air in the system a place to be captured. Fill it up to the line while the engine is running with the cap off. Put the cap on and run it, check/fill it again after running. Check on the levels every day for about a week or so, then once every month thereafter (normal maintenance) to ensure it stays up to the line.

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