Newsletter Signup
Stay up to date on all the latest news from Boston.com
What steps should I take before changing my truck’s battery?
John Paul, AAA Northeast's Car Doctor, answers a question from a reader preparing to put a new battery in their pickup truck.
Q. I want to change the battery in my 2019 Toyota Tacoma but I have been told I have to apply power to my computer before I disconnect the battery. Could you explain to me how to do this?
A. When changing a battery it is always advisable to use a memory saver. This can be a device that plugs into the OBD under dash connector, or attaches to the jump start terminals on some cars. At AAA we teach our technicians to use their jump-packs. They attach the positive lead of the pack to the positive battery cable and the negative lead to a ground. Then carefully remove the cables (use a rag to insulate the “hot” positive cable, clean the connections, remove and install the new battery. On your Toyota if you don’t do this, you will need to reset your clock and radio presets, and there may be a start/stall for the initial start with the new battery until the computer relearns the idling speed.
Advertisement:
Q. Do you happen to know of a local repair shop that can rebuild the cluster on my 2004 RAM pickup?
A. AAA has approved repair shops that may be able to perform the repairs. Typically what will happen is the shop will remove the faulty cluster and send it out to be repaired. Some time back I had a technician on my radio program from an electronics rebuilder in Georgia call Upfix. You can find that interview and more than 500 programs here.
Q. I received a portable hydraulic trolley jack for Christmas and plan on throwing it into the trunk of my car, where I hope to never use it. It’s got a little bit of weight to it — 18 pounds, to be exact — and I was wondering what the impact (if any) of carrying this extra weight around will have on my gas mileage. I drive a 2019 Toyota Camry SE which gets about 33 mpg (much of it highway driving). Your thoughts?
Advertisement:
A. A good jack and lug wrench are very handy and can make changing a flat tire much safer, although you still need to be aware of jacking points. Regarding the extra weight, 18 pounds is about the equivalent of carrying three gallons of gas. You most likely won’t see any difference in gas mileage when your fuel tank is one quarter full or half full. I would take some care to secure the jack in the trunk. You don’t want it to become a flying object in a crash.
Q. I have a 2011 Chevrolet Avalanche and the fuel pump needs to be changed. I am located in Massachusetts. Could you tell me approximately how many hours it would take a mechanic to change the fuel pump (in the tank) of this Avalanche? What is the labor rate these days that a garage would get? I am looking for just a rough estimate before I call a garage.
A. Depending on where you go (new car dealer or independent shop) I use an average of $130 for standard labor and $175 for diagnostics and some specialized work. It will take about three hours for the install, and the parts can vary depending on what kind and quality. Looking online, the pump with the float can range from$100 to $300. Using standard labor guides and a factory part the total cost could be as much as $1,300.
Advertisement:
Q. I generally don’t read about car repairs, but approximately two weeks ago I spilled some spaghetti with meat sauce on the leather seats on my new car. As it turns out that week you mentioned several car cleaners in your column. I bought one of them – Meguiar’s – and it worked perfectly. Thank you for your insightful recommendations. You now have a new reader.
A. Thanks, and I have always had good luck with Meguiar’s products. From time-to-time different companies will send me products to try out, some work better than others. I have found over the years Meguiar’s products work as advertised and they are what I buy and use.
Q. I have a 2017 Buick Regal and one of the tires was stabbed by strangers at the shopping mall. It was terrible and I couldn’t believe it when we came out. It was completely flat. I am thinking about buying a Nokian tire. Is this the correct tire for my car?
A. I have been using Nokian tires on my car for about a year now and they have been very good. Unless you are replacing a pair of tires, I would try to match the other tires on the car. Replacing just one tire with a different brand and tread design can cause some odd handling and even uneven braking in slippery conditions. If you are replacing two tires, the Nokian tires are a good choice.
Advertisement:
Q. We own a 2020 Subaru Crosstrek Limited with the start/stop feature. The battery failed when the car was seven months old because it wasn’t started for several weeks during the COVID lockdown. Subaru replaced the battery and said the OEM battery with a rating of 620 cold cranking amps wasn’t really suited for the electrical requirements of this model. It’s now three years later and the battery again failed because we were away for three weeks and it wasn’t started during that time. I’d like to replace it with a more powerful (non-Subaru) battery but am confused by the start/stop feature. Will any Group Size 35 battery be okay?
A. Most group 35 batteries have a reserve capacity of 90 minutes or so. In the case of your Subaru, reserve capacity is as important as CCA. Considering how you drive I would consider switching to an AGM battery. Most vehicles with start/stop have AGM batteries. Doing a quick search on AAA and other battery sites, it seems as if you can easily find a group 35 AGM battery that has a rating of 650 CCA and 100 minutes of reserve capacity. In theory a battery like this should allow your car to sit for a month, providing there is no abnormal parasitic drain.
John Paul is AAA Northeast’s Car Doctor. He has over 40 years of experience in the automotive business and is an ASE-certified master technician. E-mail your Car Doctor question to [email protected]. Listen to the Car Doctor podcast at johnfpaul.podbean.com.
To comment, please create a screen name in your profile
To comment, please verify your email address
Conversation
This discussion has ended. Please join elsewhere on Boston.com